I use Autodesk Sketchbook on the desktop (PC), with a Huion tablet (medium). I do not have a fancy iPad Pro or Apple pen, so no tablet app for me.
Also, the program is completely free on their website now. They (Autodesk) were "excited to announce that the fully featured version of SketchBook is now FREE for everyone!" back in 2018. So there you go, no more subscription fees!
Also, I am not sure if the instructor mentioned this, but from what I could see, the Lock/Unlock function wasn't used in this tutorial? You can Lock/Unlock your symmetry lines. That way you do not move it by mistake when you are sketching out your drawings. ;) There is a lock icon to the right on the symmetry bar, as well as Show/Hide symmetry lines (eyeball icon) which hides the dotted lines, but is still active when drawing. I found those two tools most useful when symmetry was turned on. :)
I do not know if anyone else had this problem, but I was not able to use the male template that was provided. It would not save as a JPG file. :(
Anyway, here is what I was able to complete today. :)