Amazingly simple application. Can be self-hosted.
All you need is curl, but of course it can be done via webhook (so basically any online app will be able to connect), or any other way to simply PUT/POST an http request.

Similar goals to gotify, but 3 major differences:

• Provides hosted instance to quickly get you started testing it out
• uses publically accessible notification streams so less secure especially on the hosted instance
• has a broader scope for features with e.g. file attachments and click actions for notifications