You should install F-Droid. lmoat every app on there is completely ethical, and there are many (not enough but many).
Many of the ones that require a server side connect to your self hosted server instead of some central server on the cloud, which is a reason they will never get popular, but sounds perfect for you. There are some that use central servers, and this fact will be clearly stated in the antifeatures section. Many other F-Droid apps just work offline. And hardly any have ads.
Many of the ones that require a server side connect to your self hosted server instead of some central server on the cloud, which is a reason they will never get popular, but sounds perfect for you. There are some that use central servers, and this fact will be clearly stated in the antifeatures section. Many other F-Droid apps just work offline. And hardly any have ads.