I've been doing some digging around, and according to RCDB's records only one company has built a traditional Boomerang roller coaster - Vekoma. While other companies have built shuttle roller coasters that have a back and forth motion, usually using some sort of launch propulsion, Vekoma is the only company to use a lift chain backwards, cobra roll, loop, and spike.
The first Vekoma Boomerang was built in 1982, and is believed to have either opened in 1983 or 1984.
http://rcdb.com/3826.htm
Arrow had a hand in helping construct Vekoma's early boomerangs as well.
As for a name of a designer, none is given. Overall, 45 boomerang coasters are in operation today (not including Inverted nor Giant Inverted designs), making it one of the most popular roller coaster designs in history.
Here's a further read:
http://en.wikipedia.org/wiki/Boomerang_(roller_coaster)