Import gradients as shape fills in Sketch using Will Burn's colorfulgradients and colorincolor.

• Select Shapes
• Run using Plugins > Menu > sketch-colorfulgradients > Option
• Wait for the images to be inserted as fills

The official documentation explains how to install plugins in detail.

• Find Sketch Plugins folder using Plugins menu > Reveal Plugins Folder
• e.g. git clone /Users/dunc/Library/Containers/com.bohemiancoding.sketch3/Data/Library/Application\ Support/com.bohemiancoding.sketch3/Plugins

• Find Sketch Plugins folder using Plugins menu > Reveal Plugins Folder
• Download
• Unzip and copy into Sketch plugins folder

A big thanks to the awesome Will Burn).

MIT © Duncan Beaton