How can I make a photo look like a painting?

To make a photo look like a painting:

Tap the photo and choose the Edit pencil in the upper left corner.

In the Photopea editor, choose Filter > Stylize > Oil Paint

For fastest results, turn off the Preview button until you have selected the settings you prefer. (If you leave Preview on, the program will be delayed while every pixel is transformed each time you make a selection.)

To test an effect, turn Preview on. When you have achieved the effect you want, be sure to choose File > Save.  A new version of your photo will be saved in your album.

You can adjust the these settings for the Oil Paint filter:

Radius
Adjusts the size of the strokes in pixels.

Cleanliness
Adjusts the length of the strokes in pixels.

Scale

Adjusts the relief or apparent thickness of the paint, moving from a thin coat at 0 to a thick coat, giving luscious Vincent van Gogh-style paint globs, at 10.

Bristle Detail
Adjusts how much of the paintbrush-hair indentation is apparent, moving from soft at 0 to leaving strong grooves at 10.

Lighting

Shine
Adjusts the brightness of the light source and the amount of bounce off the paint’s surface.

Angle
Adjusts the incidence angle of the light (not the brushstroke). This setting is important if you are incorporating the oil painting into another scene.