Android Keyboard (AOSP) for Android - Download the APK from Uptodown
How do I add a number row to AOSP keyboard? : r/LineageOS
Solve Unfortunately Android Keyboard Has Stopped Error on Android Phone - YouTube
Top 7 Ways to Fix Android Keyboard (AOSP) Has Stopped
Simple Keyboard is an actively developed, open source fork of the AOSP Keyboard for those looking for a less bloated, more responsive, basic keyboard with minimal permissions : r/Android
Blog - How to build a software keyboard if you're the only engineer in a startup