So I figured this is probably better in its own thread, even though it's about SmartGlass.
Since the other two SmartGlass enabled games are disc only (Forza Horizon and Dance Central 3), I decided to give Home Run Stars a try when it became available this morning. I only did a very basic runthrough of it, but the game itself is really buggy. My Kinect "cursor" frequently disappeared. The worst instance was when I went to the leaderboard page and there was no way I could see to get back out of it.
Anyway from the short time I played with it, it's basically a very simple baseball game, similar to Wii Sports' baseball. The SmartGlass mode is kind of neat though; the second player picks pitches on the phone or tablet, and then taps a few circles to determine the power, and the first player swings with Kinect. It's definitely something I could see being pretty entertaining for a while with large groups of people.