The new version, released yesterday, now supports Android tablets running up to version 4.04 (Ice Cream Sandwich). This version also includes performance enhancements and bug fixes. Last month when HBO Go got an update the only tablet that was supported was Amazon's Kindle Fire. The interesting point is that this update comes at a time when Android 4.1 has been released with Nexus 7 tablet and the app doesn't yet support Android 4.1.
HBO should have supported 4.1 to attract those users who are ordering Nexus 7. It will be interesting to see when HBO will push an update to support Jelly Bean.