This free and ad-free app takes a random walk painting dots around a digital canvas. Just swipe the canvas and watch it go - if the painting process veers off one edge, it will carry on from the other side.

You can adjust the following settings:

Number of dots to be painted - from 100 (default) to 10,000*

'Paint' colour and opacity, via four sliding bars

'Brush' size - from 5 to 40 pixels wide (default is 10)

The range of possible next directions, selected by choosing one of the buttons to the left (relative to the last direction).

* 10,000 dots takes my ageing Nougat roughly six minutes.

While painting is under way, contact is disabled (except for the STOP button at bottom right), after which you can save what you've done to your device, or clear the canvas and start again with an option of a black or white background.

Designed using the Droidscript IDE.