People face a massive project and freeze because they don't know where to start. Existing to-do apps are empty lists you populate yourself. The demand is for an AI tool where you describe what you need to accomplish in natural language, and it breaks it into ordered, time-estimated sub-tasks with dependencies. An HN user called it 'Cursor for to-do lists.' The ADHD community especially needs this, where executive function challenges make task breakdown the hardest part.
builder note Goblin.tools is your reference implementation and your proof of demand. It's free, single-purpose, and beloved by the ADHD community. Build the persistent version: describe a project, get the decomposed task tree, check things off as you go, and the AI re-estimates remaining time as you progress. The recipe photo scanning use case from the HN thread is a great demo: photograph a recipe, AI creates 'buy ingredients, prep veggies, marinate protein, cook' sub-tasks with time estimates. Start with the decomposition engine, add persistence second.
landscape (4 existing solutions)
Task management apps provide the list. AI assistants provide conversation. Nobody combines them: describe a project, get an ordered task tree with time estimates and dependencies, then manage that tree as your actual to-do list. Goblin.tools proves the AI decomposition concept works for ADHD users but stops at one-shot breakdowns with no persistence. The gap is Goblin.tools' decomposition intelligence inside a real task manager with project context, history, and time tracking.
Todoist AI Assistant Added AI features in 2024 for task suggestions and natural language input. But the AI suggests individual tasks, it doesn't decompose a complex project into an ordered, dependent task tree with time estimates. Still fundamentally a manual list. Amazing Marvin Most ADHD-friendly task manager with extensive customization. Has task breakdown features but they're manual. No AI decomposition. The irony: configuring Marvin itself requires significant executive function. Workflowy Infinite outliner that's great for manual task decomposition. Clean, fast, minimal. But purely manual. No AI, no time estimates, no dependency tracking. The user must do all the thinking. Goblin.tools Free AI task decomposition tool specifically for ADHD users. Breaks one task into sub-steps. Closest to the need. But web-only, no persistent task management, no time estimates, no project-level decomposition. Each decomposition is standalone with no history. sources (2)
productivityAIADHDtask-managementproject-planning
People accumulate thousands of files across laptops, external drives, and cloud storage with no organization. AI file sorters exist but all work on a single device and automatically move files without asking. An HN user requested an AI assistant that scans files across multiple devices, proposes an organization plan with before/after preview, and only executes after human approval. The 'undo-friendly' requirement rules out every existing tool.
builder note The cross-device part is the hard problem. Use Syncthing or a lightweight agent on each device that indexes file metadata (name, type, size, creation date, content hash) without moving anything. The AI proposes an organization plan based on the unified index. The user reviews a before/after tree view and approves. Only then do files move. The approval workflow is what differentiates this from every 'auto-sort' tool that terrifies users who fear losing files.
landscape (4 existing solutions)
AI file organizers in 2026 all work on single devices and single folders. None scans across multiple machines, proposes a unified organization scheme, and waits for human approval before moving anything. The cross-device gap is fundamental: your Downloads folder on your laptop, your project files on your desktop, and your phone photos all need to be organized together, not in isolation. AI File Sorter's preview workflow is the right UX pattern but needs cross-device reach.
AI File Sorter Cross-platform desktop app with preview-based workflows and local AI (LLaVA). Closest to the need with dry-run mode. But single-device only, no cross-device scanning, and no persistent organizational rules that learn from your approvals. Sorted App Takes a messy folder and organizes it into subfolders. Simple and effective for single folders. But no preview/approval step, no cross-device support, and no content-aware organization beyond file type. Sparkle Mac-only cleaner and file organizer with AI. Good for finding duplicates and reclaiming storage. But focused on cleanup/deletion, not intelligent organization. No cross-platform support. Dropbox Smart Sync AI-powered file management within Dropbox's ecosystem. But only works with files already in Dropbox. Cannot organize local files across devices. Requires Dropbox subscription. sources (2)
productivityAIfile-managementlocal-firstcross-platform
People drowning in debt know they should track their payoff plan but existing apps are either bare-bones calculators or full budgeting suites like YNAB. Users on r/personalfinance want a tool that makes paying off debt feel like a game: visual progress bars, milestone celebrations, scenario modeling for bonus payments, and 'did you know' financial tips. An HN user specifically requested Google Sheets integration and a non-depressing interface.
builder note The Debt Free Charts business proves people will pay for motivation even in physical form. The digital version needs: input your debts, pick a payoff strategy (snowball or avalanche), see a beautiful progress visualization that updates as you log payments, and get a 'what if I add $X this month' slider that shows how much faster you'd be debt-free. Google Sheets as a data backend is genius for the MVP. No bank integration needed. Manual entry keeps it simple and private.
landscape (4 existing solutions)
Debt tracking splits into calculators (Debt Payoff Planner, Undebt.it) that are functional but uninspiring, and full budgeting suites (YNAB) that are overkill. Physical debt charts (Debt Free Charts) prove people crave visual, emotionally rewarding progress tracking. Nobody has built a mobile-native debt payoff app that combines visual motivation (progress art, milestone celebrations), scenario modeling (what-if calculations), and lightweight financial tips without requiring a full budgeting system.
Debt Payoff Planner Most popular debt app with progress charts and milestone notifications. But the UI is functional, not motivational. No scenario modeling for 'what if I put my tax refund toward this debt.' No social/community features. Undebt.it Eight different payoff methods (snowball, avalanche, etc.) with good tracking. But web-only, dated interface, and no mobile app. The experience feels like a spreadsheet with a skin. YNAB Has a loan payoff planner and goal tracking. But YNAB is a full budgeting system at $109/year. Users who just want to track debt payoff don't want to learn zero-based budgeting methodology. Massive over-investment for a single goal. Debt Free Charts (physical) Proves the motivational visual concept works. Users buy physical coloring charts to track debt progress. But analog-only, no automatic calculations, no scenario modeling, no integration with actual financial data. sources (2)
financedebtmotivationconsumervisualization
SimplePractice restructured pricing in 2022, moving telehealth out of the $29 Starter plan. Most solo therapists need the $69 Essential plan, which actually costs $89-94/month with clearinghouse fees and payment processing. TherapyNotes offers flat $49/month but is still designed for insurance-billing practices. Solo private-pay therapists who don't bill insurance need scheduling, notes, a client portal, and HIPAA telehealth for under $30/month. CoralEHR launched a free tier but is very new.
builder note The wedge is private-pay simplicity. Strip out insurance billing entirely. A solo therapist needs: appointment scheduling with reminders, session notes with templates, HIPAA-compliant video calls, a client portal for intake forms, and payment collection. That's it. No claims, no clearinghouses, no ERA processing. Build on Jitsi (open-source video) and Stripe for payments. The HIPAA BAA with your infrastructure providers is the compliance bar, not the feature set.
landscape (4 existing solutions)
Therapist practice management is dominated by SimplePractice and TherapyNotes, both designed for insurance-billing practices. Solo private-pay therapists overpay for features they don't use. SteadyPractice and CoralEHR are attempting to serve this niche but are very early. The gap is a proven, HIPAA-compliant tool that includes scheduling, notes, telehealth, and a client portal at $15-25/month with no insurance billing overhead.
SimplePractice Market leader but $69/month Essential plan is minimum viable tier. $29 Starter lacks telehealth, insurance billing, secure messaging, and treatment plans. True cost with fees: $89-94/month. Overkill complexity for a solo therapist seeing 15-20 clients/week. TherapyNotes Flat $49/month for all features with no feature gating. Superior clinical note templates. But still designed around insurance billing workflow. Private-pay therapists navigate features they don't need. SteadyPractice Most affordable at $9.99/month or $79.99/year. But very early stage, limited feature set, and unclear HIPAA compliance depth. May not include telehealth. CoralEHR Genuinely free tier with unlimited clients, scheduling, client portal, and HIPAA video calls. The most disruptive entry. But brand new, unproven reliability, and unclear sustainability of free model. sources (2)
healthcaretherapypractice-managementHIPAAsubscription-fatigue
HVAC, plumbing, and appliance repair technicians rely on memory and experience to diagnose equipment in the field. YC's Spring 2026 RFS identifies this as a high-willingness-to-pay vertical with low tech competition. The product: photograph the equipment, AI identifies the model and likely issue, provides step-by-step repair guidance. No specialized hardware needed, just a phone camera and a knowledge base.
builder note The knowledge base is the moat, not the AI. Start with ONE equipment category (residential HVAC is highest-value) and build a structured diagnostic tree for the 20 most common units. Partner with experienced technicians to validate the repair steps. The photo recognition gets you the equipment model. The diagnostic tree gets you the repair. Charge $29-49/month per technician. Trade workers will pay for tools that make them faster.
landscape (4 existing solutions)
Field service management tools handle scheduling and invoicing but not repair knowledge. Enterprise AI platforms (XOi, Augmentir) provide visual diagnostics but are priced for large companies. Independent technicians and small shops (1-10 trucks) have no affordable AI diagnostic tool. The gap is a mobile app that uses phone camera + equipment model database to provide step-by-step repair guidance without enterprise contracts.
XOi Technologies AI-powered field service platform with visual documentation. But enterprise-priced, requires integration with existing FSM software, and designed for large HVAC companies with 50+ technicians. Not accessible to independent contractors. FieldPulse Field service management with scheduling, invoicing, and customer management. But no AI diagnostic capability. It manages the business side, not the repair knowledge side. YouTube/Manufacturer Manuals Technicians currently search YouTube or download 200-page PDF manuals in the field. No structured diagnostic flow. Finding the right video for the right model and symptom takes longer than the repair itself. Augmentir AI-powered connected worker platform for manufacturing. But focused on factory floor assembly, not field repair. Enterprise pricing and implementation. Not designed for independent HVAC or plumbing contractors. sources (2)
tradesfield-serviceAIHVACvertical-SaaS
Small metal fabrication shops (5-20 employees) generate quotes manually in spreadsheets because existing quoting software starts at $1,000/month. Paperless Parts dominates but is priced for larger operations. YC's Spring 2026 RFS specifically calls out metal mill software as an opportunity, noting lead times of 8-30 weeks and fragmented production planning. Shops with 10-50 employees need quoting at $200-500/month, not enterprise pricing.
builder note Don't build an ERP. Build a quoting calculator that reads CAD files. The 5-person shop owner doesn't want to manage inventory or schedule jobs in your software. They want to upload a STEP file, pick a material, and get a PDF quote they can email to the customer in 5 minutes. Open-source CAD libraries (Open CASCADE) handle the geometry parsing. Price per-quote or flat monthly to undercut Paperless Parts by 5x.
landscape (4 existing solutions)
Machine shop quoting software is mature for large operations ($1K+/month) but inaccessible to small shops that still use Excel. The gap is a lightweight, affordable ($200-500/month) quoting tool that imports STEP/DXF files, auto-estimates machining time, and generates professional quotes without requiring an ERP migration or dedicated estimator.
Paperless Parts Market leader with instant CAD-based quoting. But pricing starts at $1,000/month, designed for shops with 20+ employees and dedicated estimators. Overkill for a 5-person CNC shop doing 50 quotes/month. DigiFabster Instant quoting from CAD files with customer-facing portal. Supports CNC, 3D printing, laser cutting. More accessible than Paperless Parts but still oriented toward shops with web storefronts. Pricing not transparent. E2 Shop System Full ERP for small-to-mid shops with quoting, scheduling, and inventory. But it's an ERP, not a quoting tool. Setup takes weeks. Requires training. Most small shops only need the quoting module. QuoteCAD Manufacturing CAD-driven quoting that analyzes geometry and tolerances. Good for CNC-specific quotes but limited material database and no integration with common shop management workflows. sources (2)
manufacturingCNCquotingsmall-businessvertical-SaaS
Most adaptive learning tools use basic spaced repetition, which only optimizes review timing. Item Response Theory (IRT) models actual learner ability and question difficulty on continuous scales, enabling genuinely personalized difficulty progression. A builder on HN shipped Talimio with IRT-based adaptive practice and got praised for doing what EdTech companies skip. 71% of universities will deploy adaptive platforms by 2026 but the consumer/self-learner space is underserved.
builder note The IRT math is well-documented in academic literature and open-source R/Python packages. The hard part isn't the algorithm, it's the content. Use LLMs to generate practice items (like Talimio does), then calibrate difficulty parameters as users interact. Start with one high-demand subject (programming, math, or language) where you can validate the adaptive model before going multi-subject. The open-source angle differentiates from every locked-down EdTech product.
landscape (4 existing solutions)
Adaptive learning bifurcates into enterprise products with real psychometrics (Carnegie Learning, locked to institutions) and consumer apps with basic spaced repetition (Anki, no ability modeling). Duolingo proves IRT works at consumer scale but keeps it locked to languages. The gap is an open, general-purpose adaptive learning platform using IRT that any self-learner or independent educator can use across any subject.
Anki Gold standard for spaced repetition but uses SM-2 algorithm, not IRT. Treats all cards as equal difficulty. No ability modeling. The UX is famously hostile to non-power-users. Duolingo Uses a form of IRT internally (Birdbrain system) but locked to language learning. Not a general-purpose adaptive platform. Gamification model not suitable for all subjects. Carnegie Learning MATHia Uses IRT and is deployed in 2,400 US schools with 600K students. But enterprise-only, math-only, and not available to individual self-learners or independent educators. Talimio First mover in consumer IRT-based adaptive learning with LLM-generated courses. Open source on GitHub. But single developer, very early stage, limited subject coverage. sources (2)
educationadaptive-learningAIpsychometricsopen-source
American expats face a uniquely painful tax situation: filing in both the US and their country of residence, with forms that consumer software can't handle. TurboTax lacks Form 8833 for treaty provisions and doesn't file FBARs. Big expat firms charge $500-1,200 per return and assign random preparers. An HN user explicitly said they'd pay $1-2K annually for comprehensive self-service software.
builder note The $1-2K willingness to pay is real because the alternative is a $500+ CPA who might still mess it up. The technical challenge is tax law complexity, not software. Partner with an enrolled agent to validate form logic. Start with the most common expat scenario (US citizen in Europe, employment income only) and expand to investments and multi-country situations. The FBAR filing integration alone would differentiate you from TurboTax.
landscape (4 existing solutions)
Expat tax filing splits into inadequate DIY software (TurboTax can't handle key forms) and expensive human preparers ($500-1,500/return with variable quality). MyExpatTaxes is the only self-service tool designed for expats but can't handle complex multi-country situations. The gap is comprehensive self-service software covering ALL expat forms (2555, 1116, 8833, FBAR, 8938) with strategic optimization (FEIE vs FTC analysis) at a price between DIY software and human preparers.
MyExpatTaxes Best self-service option, uses question-based flow instead of raw forms. But limited to straightforward expat situations. Cannot handle complex investment income, Form 8833 treaty positions, or multi-country obligations beyond US + one residence country. TurboTax Supports Form 2555 and 1116 but lacks Form 8833 for treaty provisions and cannot file FBARs. Not designed for expats. Misses critical optimization opportunities like housing exclusion limits. Greenback Tax Services Full-service expat tax firm at $500-1,200 per return. Users get assigned random preparers, communication is slow during peak season, and complex situations get squeezed into standardized templates. FileAbroad Boutique expat firm with strategic FEIE vs FTC analysis. Good service but $500-1,500 per return and stops taking clients during peak season. Not self-service. sources (2)
financetaxexpatinternationalcompliance
When Yummly shut down, users could only export recipes one at a time. Thousands lost years of saved collections overnight. There is no standard format for recipe data and no tool that imports from one platform and exports to another. Every recipe app is a data silo. Users want a personal recipe vault they own, with importers for every major platform.
builder note The JSON-LD Recipe schema (schema.org/Recipe) already exists as a web standard. Build an app that stores recipes in this format locally, with importers that scrape from Paprika's export, Plan to Eat's format, and any URL with schema.org markup. The moat is the importer library. Every time a recipe app dies or raises prices, you get a wave of new users.
landscape (4 existing solutions)
Every recipe app is a data silo. Tandoor proves self-hosted portability works but demands technical setup. The Yummly crisis proved that cloud recipe collections can vanish overnight. Nobody has built a consumer-friendly recipe vault with universal importers (Paprika, Mealime, AllRecipes, Samsung Food) and standard export formats (JSON-LD Recipe schema, PDF, plain text).
Paprika (import) Can import from URLs one at a time. No bulk import from other platforms. No export to competing formats. Your recipes are locked in Paprika's proprietary format. Plan to Eat Built a Yummly import tool but it only works for recipes that still redirect to original blog URLs. Saved notes, modifications, and personal recipes are lost forever. Samsung Food (Whisk) Free with recipe saving and 4.5M community members. But no import from other apps. Another data silo with no export guarantee. Tandoor Recipes Self-hosted, open source, supports import from several formats. Closest to the portability ideal but requires Docker setup. Not accessible to non-technical home cooks. sources (2)
cookingdata-portabilitylocal-firstconsumeropen-standard
Whirlpool killed Yummly in December 2024, orphaning millions of home cooks. Existing replacements still require users to browse recipes and drag them onto calendars. The actual demand is an app that knows what's in your fridge, remembers what you cooked last week, and TELLS you what to make tonight. No existing app combines pantry awareness, taste memory, and proactive meal decisions.
builder note Don't build another recipe database. Build a kitchen memory layer. The MVP is: photograph your fridge, get three dinner options ranked by what needs to be used first, tap one, get the recipe. Persistent state between sessions is the moat. Monetize with a one-time purchase to capture the anti-subscription crowd that made Paprika popular.
landscape (4 existing solutions)
The meal planning space split after Yummly's death: recipe organizers (Paprika) for people who know what they want, and AI generators (CWR, Ollie) for people who don't. Nobody combines persistent pantry tracking, taste memory across sessions, and proactive 'here's what you should cook tonight' decision-making. The decision-making gap is the real product.
Ollie Learns family preferences and can process pantry photos. Closest to the need but subscription-based and iOS-focused. No persistent memory between planning sessions. Paprika Reddit's favorite because it's a one-time purchase. But zero discovery, zero AI, zero recommendations. You must already know what you want to cook. Cooking with Robots Generates original AI recipes from fridge photos. But no persistent pantry tracking between sessions, no taste memory, and no proactive meal suggestions. Mealime Rigid serving sizes, no pantry tracking, recipe variety plateaus after a few months. Users report seeing the same recipes rotate. sources (2)
cookingmeal-planningAIconsumersubscription-fatigue