PhotoGimp is not a plugin but a set of config files (including random session files from the dude that made it XD)

One thing missing is algorithmic tools like auto-removal or auto-selecting people and objects. It is not very complex but I dont know a gimp plugin for that

Tox did their own insecure crypto and got roasted by the Wireguard dev, now they are apparently rewriting it.

I agree that Matrix is complex but personally never had issues with key verification. Just try to restart it, maybe on the other device?