Boost case enables Apple users to enjoy the progressively more mobile, active, world they know and to get the most out of their device. The Boost Case gives you the option of both i.e. a battery when you need it and a slim case to make the phone look slimmer when the battery isn't needed.

Boost Case has a rotund shaped opening at the back side that acts as small hole for the sliding lock on the 2.2-ounce, 1900 mAh lithium polymer battery. The Boost Case comes in two pieces rather than single piece batteries that need to be removed before using them. One piece stays on the phone all the times while the other one is the actual extended battery. It actually charges the iPhone directly and gets charged through standard micro USB. The extended battery can be removed when the phone is charged without keeping your phone unsecured or unprotected.
It takes around three hours to charge from empty to full and around one and a half hour to transfer the power to the iPhone from the extended battery. The slim case apart from protecting the iPhone from abrasion serves as adapter for the extended battery charger. The Boost Case is available at Amazon at a price tag of $79.95 and the case alone is priced at $34.
Via : LifeHacker