This app lets you convert numbers to their word form up to 69 digits, and it can convert decimals. It lets you change the decimal format and share or copy the output. There is a setting for capitalizing the output. The app could be useful when writing numbers on bank checks.
Get the full version to record your number history and choose between a dark and light theme.
Full Version Link
Light-Weight: Yes, < 1MB
Input Methods: touch, keyboard, mouse
Descriptor: number to words converter
Multi-Window Support (Android 7+): Yes