Hey!
I use Autodesk Sketchbook (Free version on mobile). It’s easy-to-use, and gives efficient results. However, you can only add a few layers in the free version, and have limited brushes/tools. You can upload images, add text (although I prefer Phonto for text), and save your work as many times as you want. It gives a clean look to your edit, and can be used to give even the most minute details.
It’s also available for desktop, and has more features/brushes on the desktop (free) version than the mobile (free) version.
It also has a paid version, with of course, more brushes and tools such as a recording feature, more layers to work with, etc.
Hope this helps 