POEditor - The translation and localization management platform that's easy to use *and* affordable!
Weblate - Weblate is a free web-based translation management system.
Poedit - Poedit translations editor. The best way to translate apps and sites.
Crowdin - Localize your product in a seamless way
Lokalise - Localization tool for software developers. Web-based collaborative multi-platform editor, API/CLI, numerous plugins, iOS and Android SDK.
JSONBabel - JSONBabel is a tool for translating *.json language files.