Joplin is an open source note-taking app. Capture your thoughts and securely access them from any device.

 https://joplinapp.org/

Looks like a capable replacement for evernote-type apps. 

An open source note taking and to-do application with synchronisation capabilities

 https://joplinapp.org/

Sorta like an opensource evernote

Note Taking Apps Showdown: Google Keep vs. Evernote

https://zapier.com/blog/google-keep-vs-evernote/
Sure with google keep had an API.

Remember Everything with Evernote: 30+ of the Best Tips and Tricks

https://zapier.com/blog/how-to-use-evernote/

I use #evernote, but clearly I'm not a power user as this article has extensive how-tos.