Mophie ( says the juice pack plus is now compatible with all iPhones. It costs US$99.95.

The enhanced capacity iPhone 4 rechargeable external battery case more than doubles the time to rock, talk, surf and send, according to the folks at mophie. In tandem with the launch, the company has designed a special edition purple juice pack plus case.

The plus boasts a 2,000 mAh battery capacity. Designed for iPhone 4 power and protection, the case has a thin and light-weight design, a dual injected rubber grip, and is only one millimeter thicker than mophie’s flagship case, the juice pack air. The special edition purple juice pack plus, of which only 3,000 were produced, features a purple band around the edge of the case. Additional colors include black-on-black, and black with cyan, magenta or yellow banding.