Lokalise - Localization tool for software developers. Web-based collaborative multi-platform editor, API/CLI, numerous plugins, iOS and Android SDK.
Crowdin - Localize your product in a seamless way
POEditor - The translation and localization management platform that's easy to use *and* affordable!
Phrase - A platform offering AI-powered translation tools for localization at scale.
Smartling - Website localization & translation
Weblate - Weblate is a free web-based translation management system.