Download .zip from here, unpack and double click on AutoDraw.sketchplugin.
Doodle some stuff with Pencil tool, select shape layers and hit ctrl+shift+m (m stands for Magic). If you edited your mockup, re-select the layers and hit ctrl+shift+m once again.
We were testing it on Sketch 43.1, it might work on older versions too.
A.I. Powerhouse provided by autodraw.com and A.I. Experiments by Google.
Sketch plugin by sympli.io
This is unofficial and experimental integration.