Google isn't done trying to improve exposure for tablet-optimized Android apps. As of November 21st, Google Play will default to showing "Designed for tablets" apps when owners of those bigger devices browse top lists. Customers can still find phone-sized software if they like, but those titles will be marked as "Designed for phones." While simple, the switch could represent a big help to tablet users building their app collections -- and developers looking for a little extra attention.