[Free] Google Play Books, https://itunes.apple.com/us/app/google-play-books/id400989007?mt=8 In addition to all the normal ebooks, you can rent textbooks for up to 180 days and access them through Google Play apps across devices.
[Free] iBabylon, https://itunes.apple.com/us/app/ibabylon/id353952483?mt=8- You can translate words, paragraphs, and entire documents, while also receiving dictionary and Wikipedia results. Also has text-to-speech feature and grammar checking.
[Free] Find My iPhone at https://itunes.apple.com/us/app/find-my-iphone/id376101648?mt=8 See where your devices are, remotely make them play a sound to help you find them, or remotely lock or wipe your lost or stolen device.
[Free] Free Graphing Calculator at https://itunes.apple.com/us/app/free-graphing-calculator/id378009553?mt=8 Scientific calculator, graphing abilities, unit conversion, pre-programmed constants, and formula library.