See git retire.
See Debugging patterns.
The app GrafNCalc83 is wonderful. It emulates the TI-83 Plus and beats all other calculator apps I’ve tried. (Okay, I haven’t tried that many. But I’ve tried PCalc, for example, and PCalc doesn’t cut it for me.)
I’m not getting paid for this. I’m just giving this app a shout-out, because I’ve been enjoying using it.