Show apps for specific older Android versions
Due to a recent Letsencrypt certificate mess all F-droid clients no longer work on devices below Android 6. It is now close to impossible to search for apps suitable for these older devices.
If you could iclude an option to show all apps running on a specified Android version, your app would be very useful to owners of old devices. They can then search on a newer device and then downloaded on the target device by browswer. Now there is no way I know of to search/browse apps for old devices.
Your app has the routines for this anyway, just replace the version of the device running your app by the version in the optional setting.