Wrist Releases are hugely popular with people starting archery and also with hunters. Even so they have had huge success on the tournament scene as well with Dietmar Trillus winning both the world target and Vegas with a wrist release.
Wrist releases are a favorite with hunting mainly due to them being attached to the wrist, so you can stalk game without losing the release.
There are hundreds on the market and just as many ways to use them.
This good video by B3 Archery's Chris Cooper gives a nice rundown on how to use this style of release effectively.