Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Crowdin - Localize your product in a seamless way
Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.
POEditor - The translation and localization management platform that's easy to use *and* affordable!
Google Keep - Capture notes, share them with others, and access them from your computer, phone or tablet. Free with a Google account.
Lokalise - Localization tool for software developers. Web-based collaborative multi-platform editor, API/CLI, numerous plugins, iOS and Android SDK.