Localizer - Free self-hosted open-source crowd-translating service
AnySoftKeyboard - Android (f/w 1.5+) on-screen keyboard for multiple languages.
Google Translate - Google's free service instantly translates words, phrases, and web pages between English and over 100 other languages.
Gboard - Google-powered keyboard with search, GIFs, emojis and more!
Lingvanex - Translation apps for business, travels, professional translators, students and free style people.
FlorisBoard - An open-source keyboard for Android.