Postman - The Collaboration Platform for API Development
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.
StopLight - Stoplight is an API Design, Development, and Documentation platform that enables consistency, reusability, and quality in your API lifecycle, all with an easy, enjoyable developer experience.
Standard Notes - A safe place for your notes, thoughts, and life's work
Mockoon - Mock servers in seconds
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.