Hey everyone, I'm looking at iPhone 5 battery cases to extend the life of my phone. It seems to me most of the options are still pretty bulky and I need something slim. I found one, but it doesn't have a lot of reviews. It's this one. http://amzn.com/B00A6YEUXI I found a few videos online about it but I'm not really convinced yet. I like how sleek it is and I've heard good stuff about this company. Thoughts?