#Carnet is a free open alternative to Google Keep. It includes text, images, audio, todo lists and syncing features.
It's currently available for Android (on Google Play and F-Droid), Linux, and NextCloud.
You can follow it here:
You can find out more and contribute on its git page:
The lead developer is here:
mastodon.at is a microblogging site that federates with most instances on the Fediverse.