Awesomely useful, for some
A fantastically detailed and useful app for those visiting theme parks, with a couple of caveats. First, and most importantly, Thrill Seeker currently only has information for 20 parks, limited to the United Kingdom and Florida, USA. This means, for instance, that it includes a wealth of information for those visiting Walt Disney World, but none at all for Disneyland. Thankfully, the developer was wise enough to enumerate which parks the app covers in its AppStore listing, so no one can complain of buying it needlessly. The second caveat is that the app will be much more useful to iPhone users than iPod Touch users because of the location-based service it provides. This is somewhat mitigated by the ability to manually tell the app where you are so that it can give you directions or tell you what is around you.
The bottom line is that if you are unfamiliar with the park you are intending to visit, and it is one of those included, this app is definitely worth its purchase price. Others can wait until their favorite park is included in a future update before they commit.