Homer allows you to find out what apps your friends (or people that are trending, including celebrities) have downloaded by sharing screenshots you have taken of your homescreen. The developer has given some thought to privacy, as you can hide apps, or only allow followers to see them. It's simple and straightforward and, while you could just use it to spy on your friends, it's actually quite a useful tool for app recommendation. A good addition to Homer would be the ability to search by category.