CAS Calc

★★★★★ This app is very light-weight compared to heavy contenders, like Maxima. It is ads-free and performs very well (solved some equations and integrals correctly). The only thing I miss are some aesthetical options, like font size and it could also generate MathML output (which I suppose Android could display "paper like" without crashing). Talking about output, as a simple suggestion, it could print something like "I:" and "O:" before inputs and outputs (and "E:" for error messages, or use some colours), because it can get really messy really fast when trying to make some serious calculations...

★★★★★ Can't really complain for a free app. It's very useful for getting the exact value of very large exponents! Gives all 100,000+ digits of 256^64576! (This is the ONLY app that can do that!) The algebra solver isn't very good. It can't solve 2^x=10^12, it just outputs the input on most basic equations.

★★★★★ Really recommended! Ad-free and advanced calculator! just perfect, I can do many things :)

★★☆☆☆ Does some math but is obviously incomplete

★★☆☆☆ Can't solve simple trig equations.

★★☆☆☆ Unintuitive

★★☆☆☆ Recent update fixed recent problem with statistics. Still not a full featured CAS calculator, but ok for what it does.