The latest version, 2.1, is a very recommended update, as it improves the frame rate and fixes some crash bugs by removing Game Center.
* Game Center removed. This:
*** Corrects the frame-rate and crash bugs
* All-New CD Quality Sound
* Minor Bug Fixes
* iPhone, iPod touch, and iPad.
* iOS 4.1 or later
* 453MB (may require double this for install)
It’s currently $4.99 at Apple’s iTunes Store.