So, this is probably going to sound a bit nerdy – but Wolfram Alpha really is awesome.
I actually bought this app (rather than waiting for it go come up as a free one) and it has definitely been worth the $4 it cost! It’s available on both iTunes and Google Play (slightly cheaper on Google Play).
It’s been an absolute life saver for my attempts at revisiting Maths B and Chemistry – I can type in a maths formula/equation, and it explains how to work it out – fantastic for when the BOB answers just give you the final result, not the working notes. I’ve only used it a little for Chemistry so far, but it’s been equally fantastic.
If you want to check it out before you buy it, this is the website. I use the app (mainly on my iPad) because on the website you need ‘pro’ access to see working notes etc for the maths things – whereas it seems that buying the app automatically gives you ‘pro’ access.
Typing maths formulas can feel a bit weird to start with, because you really need to over-use brackets to make it all come out correctly, but you get used to it pretty quickly.