The "v12 b1200" refers to the major version and build number. The "KF2" tag often indicates a specific modification or a signature from a third-party distribution source (like a modded or "unlocked" version).
: Allows you to add specific apps to a list; the app then sends a notification the moment those specific titles go on sale or become free.
: Tracks price changes for Android apps and games, providing a history of price fluctuations to help you decide if a "sale" is actually a good deal.