Multiling O Keyboard - Super lightweight (~ 1/3 MB) yet flexible and powerful soft keyboard.
Gboard - Google-powered keyboard with search, GIFs, emojis and more!
AnySoftKeyboard - Android (f/w 1.5+) on-screen keyboard for multiple languages.
Typing Speed Test - A simple typing test to see how fast you can type
Fleksy - Fleksy is the #1 private, white-label virtual keyboard SDK, enabling companies to create unimaginable products.
keyboardlayouteditor - Powerful, visual designer for designing and editing keyboard layouts.