Modern CSV - A CSV editor/viewer
ReqRes - A hosted REST-API ready to respond to your AJAX requests.
Tablecruncher - This lightweight, yet powerful CSV editor for Apple Mac helps you crunch all your tabular data.
JSON Placeholder - JSON Placeholder is a modern platform that provides you online REST API, which you can instantly use whenever you need any fake data.
Tad - Create sleeve and cover art for your band in minutes
JsonAPI - Application and Data, Languages & Frameworks, and Query Languages