Community plugins list, theme list, and releases of Obsidian.
I use Obsidian (no relation to Obsidian Portal as far as I know) but it's literally just a bare-bones knowledge base app that organizes markdown files. No features specifically related to TTRPGs.
Worldbuilding and RPG campaign management tool
I have some good experiences with kanka.
Appwrite - The Open Source Firebase alternative introduces iOS support . Appwrite is an open source backend server that helps you build native iOS applications much faster with realtime APIs for authentication, databases, files storage, cloud functions and much more!
A good text editing software?
2 projects | reddit.com/r/osr | 6 Jul 2022
Worldbuilding App - determining interest
1 project | reddit.com/r/rpg | 22 May 2022
2 projects | reddit.com/r/selfhosted | 17 May 2022
What tools do you use during your play sessions?
1 project | reddit.com/r/BurningWheel | 20 Apr 2022
Any recommendations for an online shared (fictional) calendar?
1 project | reddit.com/r/rpg | 14 Apr 2022