I was hinting at your last sentence. It seems, they do indeed target a lower sdk: https://gitlab.com/fmd-foss/fmd-android/-/issues?show=eyJpaWQiOiIzNTQiLCJmdWxsX3BhdGgiOiJmbWQtZm9zcy9mbWQtYW5kcm9pZCIsImlkIjoxNzI3NjgxMTN9
F-droid also warns me, the target sdk ist too old and automatic updates will not be possible.
(Thank you for the post anyhow, I didn't know the app existed before)
Für Berlin konkret: https://www.berlin.de/sen/soziales/besondere-lebenssituationen/wohnungslose/praevention