Update May 13, 2016: This is officially the best app purchase Ive ever made. That class is finished and not once was this not enough; in fact, in every way possible it exceeded my expectations. Furthermore, based on my little critique below (which was false and just user error--my error), the app developer wrote me via my website and explained how to use the help/info options which explained everything. Thank you so much! I appreciate you making this available at such a reasonable price and saving students money. ________ Previous Review: Im taking a stats class right now and after the shock of textbooks costing $275 and needing to pay ___ for access to this and another ___ for access to that, I realized that I would need a graphing calculator, which would cost another $104+. This app not only saved me about $100 but thus far, I can figure out any differences between this interface and TI-84 and it has worked. Furthermore its on my iPad so everything is bigger and clearer than it would be had I bought a TI-84. Perfect. If I had to ding one thing about this app its that there doesnt seem to be a useful "help" or "how-to" guide, and given that its not actually identical to a TI graphing calculator, I fumble a lot until I figure it out. Would love some directions! Thank you for making this great app available.