Apps for yunohost are at github, and have a standardized form of packaging...

https://yunohost.org/en/packaging_apps_intro

Apps for umbrel are at github, and have a standardized form of packaging...

https://github.com/getumbrel/umbrel-community-app-store

... I hope someone more clever with code than me can build a little bridge between the two, so that each can enjoy the selection of apps found in the other.