Crowdin - Localize your product in a seamless way

Anki - Anki is a program which makes remembering things easy. Because it's a lot more efficient than traditional study methods, you can either greatly decrease your time spent studying, or greatly increase the amount you learn.

POEditor - The translation and localization management platform that's easy to use *and* affordable!

Duolingo - Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.

Lokalise - Localization tool for software developers. Web-based collaborative multi-platform editor, API/CLI, numerous plugins, iOS and Android SDK.

Kartka - Kartka is a flash card learning tool with real-time sync, spaced repetition algorithm, and a modern and friendly interface.