I’ve just signed up to ‘Brilliant’ (if you find a techy /sciencey youtuber (eg Dr Becky) they’ll often offer a discount code.) It’s an app that helps you learn STEM subjects in a quick burst fun way. So if you have five minutes that you’d normally waste looking at social media (or the hamster wheel arguments on proone) you can spend it developing some maths (or coding for example) skills.