PowerVocab Ultra Edition contains over 1300 words and is designed for word-lovers. It can also be used to prepare a strong vocabulary for tests such as SAT, GRE, GMAT, ASVAB and so on. Words increase in difficulty as you go.
SkEye is an advanced planetarium that can also be used as a PUSHTO guide for telescopes.
This app allows teachers/coaches to keep attendance and track grades for students. Ability to send texts, emails and even call (if your devices supports calling) is simply integrated. Try out the free LITE version to test the features out before buying the app.