It is one of the strangest things. I've got QUIK SMS installed from F Droid. Yet if I go to app info, theres no Store section, saying where it was installed from. If I search for it on F Droid, it says "Install", like I don't even have it. I uninstalled and reinstalled QUIK and that fixed it, but this made me curious why it happened. The app wasn't on the latest update, so thats how I noticed. Its strange.