At this point, I have about $45 credit in my iTunes account from gift cards given to me for Christmas. I was wondering if there are any useful apps out there that I can get for physics? Whether they are good now for while I am in college, good for work in the field post-college, or both. For apps that might be sub-field specific, my current focus is high-energy astrophysics. I have looked around, but haven't found anything that seemed that great. There were lots of reference apps, but I can easily find all of that for free online and through my courses. If there were one that were really comprehensive and worth it, I'd definitely consider, but most of them seem to have so few reviews (or bad ones) that I just wasn't sure. Here is a list of the ones I have already: 1) Quickoffice - useful for editing my .docs on the go 2) Goodreader - preferred reader since I can bookmark, etc (though I use quickoffice for .docs) 3) Adobe Reader - I use this for slower-loading PDFs (Goodreader can sometimes slow to a crawl) As you can see, I don't have any that are physics specific, just ones that I use for studies, ebooks, personal notes, etc. Oh, and I do have Mathematica on my computer, so I didn't see the point in paying for it on an app as well. I also have a couple free physics apps, but none that I have found that useful. If anyone has any really useful ones, I'd appreciate it.