Modernized TouchPal-Style Swipe Keyboard That Isn't a Privacy Sinkhole
TouchPal — once a popular Android swipe keyboard — went dormant, and a Russian hobbyist forum is the only source of patched builds for Android 15/16. Users want it back because Gboard/SwiftKey are increasingly Google/Microsoft data pipelines, but installing a Russian-modded keyboard with full input-method privileges is the worst possible threat model. Real demand for a maintained, privacy-respecting alternative swipe keyboard.
Honest take: this is a hard problem. State-of-the-art swipe accuracy needs trained models on lots of typing data, and that data is exactly what users are refusing to share. Your wedge is on-device-only training (per-user) plus a respectable bootstrap model — pitch to NLnet or Mozilla's grants to fund the initial corpus. Don't ship until swipe accuracy is within 90% of Gboard or you'll get torched in reviews.
landscape (3 existing solutions)
FOSS keyboards solve the privacy half but lose on swipe accuracy. TouchPal mods solve the typing half but the privacy model is hostile. Nobody has shipped both.