What's a good Android app for explaining math concepts clearly, like a patient tutor would?

Well, after a bit of searching, I stumbled upon Gauth, and I must say, it's quite impressive actually! What I appreciate most is that it doesn't just give you the answer; it actually *explains* how to arrive at it. It's like having a patient tutor available at any time. The categorization system is brilliant; you can easily find the specific math topic you're struggling with. I've only been using it for a week, but I've already figured out three new features – who knew my phone could do this? It reminds me of having a card catalog in your pocket, but instead of books, it's filled with explanations for those dreadful equations! I find it delightfully intuitive, and I think it would be especially helpful for students preparing for exams. It's a wonderfully organized way to manage all that information. I'm recommending it to my friend's grandson who is struggling with algebra.