I was in no doubt I was going to buy this product right from the beginning. I was getting fed up of my iphone conking out after a few hours of constant texting, or listening to music on the bus. It was driving me mad!
I came across this product by chance while browsing around, and I am so glad i did! It's a phone cover for your iphone 3/gs that has a built in battery that gives your iphone an extra boost! The top of the case slides off, and you slide your iphone down onto the charger bit, then place the top back on. It has it's own plug, which can be used with the iphone charger, which not only charges the case battery, but your own battery as well. It was a bit misleading though, as the instructions said that the case came ready charge; it did not. I had to charge it myself. Basically once it's fully charged there's a little button at the bottom which lets you switch from using the case battery or your own. It's like having your own back up battery! I won't lie, it does make your iphone a lot chunkier, but that doesnt bother me, it's worth it just to have extra battery power!
Just try it for yourself and you'll never be without it again :)if only I found this ages ago, I wouldn't be driven sooo mad by the pitiful battery that apple supplied!
Another note is that the case doesnt charge as quickly as your iphone. It takes a while, but lasts forever! Lol, hope i helped :)