I just uploaded a very very very early pre-release of the app to openrepos:
https://openrepos.net/content/gmc/tasks
It hasn’t seen much testing yet, so there might be issues that may lead to data loss. I haven’t seen data loss yet in my local testing, and I am using it against my production nextcloud instance right now, but I also have very good backups 
Make sure to read the known issues before using this: