The marker functionality on iPhones is excellent. It is as simple and basic as Paint on Windows, and because it doesn’t offer you a gazillion of editing features and palettes, you can just paint/draw the basics without the allure of all the details.
When traveling without paints, I tend to make drawings on my own photos with fingers with that marker. Sometimes I’m waiting for someone and my imagination wonders (like the guys on the glass of wine) or I see some sort of a scene with people and their emotions.
I was cleaning my phone’s memory and found all the little drawings.