One thing that MUST be addressed before considering it something that people actually use is the total lack of HTTPS. This is not optional, and indeed should be mandatory like with https://f-droid.org and https://play.google.com.
I'd love to see more thinking about the detail view of the app. For example, there should be a "buy/donate" button, since many apps on fdroid have a way to accept donations. You can scrape that from the standard metadata or the `index.xml`. I think it would be best to present it like https://elementary.io does: force the user to click "Buy" with a recommended value, but let them set any value including 0.