A.R. Emoji Custom Keyboard 4+ - A.
Gboard - Google-powered keyboard with search, GIFs, emojis and more!
LingoJam - Create and have fun with unicode text translators online
Fleksy - Fleksy is the #1 private, white-label virtual keyboard SDK, enabling companies to create unimaginable products.
Cool Text - Cool Text is a FREE graphics generator for web pages and anywhere else you need an impressive logo without a lot of design work
AnySoftKeyboard - Android (f/w 1.5+) on-screen keyboard for multiple languages.