I love painting on my photos. I recently discovered the PhotoViva app. It's an easy painting app that has a nice selection of brushes.
After opening the app, you have a choice of selecting a photo from the camera roll, or take a picture with the app's camera.
You can choose to paint with a solid color, or paint using the photo as your source. You also can choose from different style brushes, brush angles and brush sizes.
You can pinch and spread the image to enlarge it for easier painting.
I brought both images into the Triply app.
I then cropped the image from three panels to two panels in the camera roll editing screen.