heres the list of apps that I used to make tutorials (You may or may not find alternatives for these)
Picsart - This app is an image editing, collage and drawing application and a social network. Picsart enables users to take and edit pictures, draw with layers and more. This app is mainly used to make any background from day to night. It is also used to make overlays and to turn any episode accesories into png form. This app helps you to make your background in a very advanced level.
Sketchbook App- The sketchbook app is the most advanced painting app availble on tablets and phones. This app lets you to edit any overlays into something advanced. I personally like this app more than any sketching apps because they have a lot of brushes and a special glowing brush whoch is really iseful if you're an editor.