I use Autodesk Sketchbook on a small iPad Air. It’s a good app and easy to use.
The actual iPad is owned by my school (they lend them to us for work) so everything is restricted. That means I have to draw everything with my fingers instead of an iPad pencil, which is slightly annoying.
I’m not that good at digital art, I mostly draw bad comics, so I don’t really have proper experience. Hope this helps anyway :)