Apps are great to help squeeze more battery life, but nothing beats an actual battery. Mophie offers three types of battery case extenders for both Android and iOS smartphones. Ranging from the $60 Juice Pack Helium to the $90 Juice Pack Plus, these devices essentially double the life of your phone instantly to at least 12 hours. The Plus version offers 120% battery life extension (compared to 75% for the Juice Pack Helium and 95% for the Juice Pack Air) and adds an extra layer of protection for the phone itself, which is worth the extra dough given how much it costs to replace these devices.