As far as I’m aware there aren’t too many apps with general info on, your better off just using the web and searching any specific info you need. If you think about it any app will just have the same info in.
there are a few species catalogues though if that’s what you need.
in terms of tank management there’s quite a few. Personally I use Aquarimate ive tried about a dozen now and that’s the one I’ve kept the longest. Record your parameters and report on them etc. Logs and livestock notes.
on iOS it’s a tenner , on android you can download the app for free if your sneaky.
I also use a tetra app for taking pictures of my test strips which then tells me the numbers , I can then type them into aquarimate.
