Wanting to add a bit of extra battery to your iPhone 4/4S, but at the same time want to keep it protected from scratches.. or worse? Well you’re in luck,as Amazon is offering a great deal on the BOOST extended battery and protective case. It’s been marked down 50%, now priced at $29.99 today. This is the best deal we could find online by up to $8. As for the case’s performance, according to reviews it seems to work as advertised. It’s been given an overall 4 star review by Amazon customers. Has a 1700 mAh battery inside the case, almost doubling performance.