Poedit - Poedit translations editor. The best way to translate apps and sites.

Amara - Amara

Aegisub - Aegisub is a free, cross-platform open source tool for creating and modifying subtitles. Aegisub makes it quick and easy to time subtitles to audio, and features many powerful tools for styling them, including a built-in real-time video preview.

Captionfy.io - Captionfy is a free Youtube community captions platform with a subtitles/captions editor that you can use to create captions for any public Youtube video.

dotSUB - The leading way to caption and translate videos online

localize.io - A collaborative translation platform to manage iOS and Android localization.