- I have a Bamboo Wacom tablet for writing on (I've had it a long time now, and it's much easier than writing on an iPad screen because it doesn't matter if your hand touches the tablet).
- I have an old Sampson C03U microphone.
- I use the program xournal for actually writing maths in.
- I use vokoscreen for capturing what I'm writing (thanks to Matthew Towers for suggesting vokoscreen!). This has a pause function (which I need).
- I use flowblade for editing the video clips together afterwards.
This is what my desktop looks like while I'm recording:
Vokoscreen is the small program in the top left and I have a terminal window open below it so that I can delete unwanted clips/bloopers immediately. The xournal file is open on the right. If you want your windows to tile like this, I can highly recommend a tiling windows manager like i3 or xmonad (I use i3). The weird blue area with the red circle segments shows you which area of the screen is being captured by vokoscreen.
This is proving much quicker and more effective than my previous attempts, which used ExplainEverything on an iPad.