Freemium games have certainly escalated throughout the existence of the App Store. The model is cheap[er] for developers, and most games like such are a big hit among iPhone gamers who can't quite spend money to whet their gaming needs. Another application like described, is Urban Rivals. You can download it on the App Store absolutely free but only for a limited time.
Of the RPG, role-playing, genre, Urban Rivals is a freemium-based application available. Having to do with cards, the game is very similar to card-trading games of the past and of the present. First off, I'd like to say one thing: if you were a Pokemon fan, not just interested in the games and shows, but also in the cards, then you'll absolutely adore Urban Rivals. You'll have a bunch of cards, each with unique (no pun intended) skills and perks, and will trade/battle with other players. Depending on skills, your cards may or may not win.
Also, very much comparable to the aforementioned card trading, Pokemon, your cards will evolve, if you will, into stronger counterparts. This happens at certain levels for each card; leveling up is done by getting experience.
I've been playing Urban Rivals, and it's got a fair amount of people currently playing, which should prove to be good. There hasn't yet been a time when I've been left hanging, which happens with other games that aren't very popular. The reason for its popularity is most likely because it's playable on both iOS and the computer.
A game like so doesn't really need good graphics, though Urban Rival's are the very opposite of bad. It's bright, enticing and polished and certainly not comparable to your average role-playing game. Great character sprites do prove to be good when played.
If you hurry, you can get Urban Rivals while it's free and enjoy the large database (about 13 million people playing to be exact) of card trading, battling, and evolution that will surely suck away your time and consume hours of your day; it's a joy to be played and the strategy involved is surely brain-tingling.