Save with Frame

The plugin will take your selected artboards and output them to a location of your choosing wrapped in an iPhone 6 frame.
You can choose 4 different colors of the iPhone 7 and iPhone 6.

iPhone 7

1. Create & Save / Open a Saved Sketch file
2. Create a new artboard sized for iPhone 7 @1x
3. Or, select artboards you want to export that are already at that size
4. Click Plugins > Save with Frame > Export iPhone 7 Assets
5. Select the color iPhone you want to frame your artboard
6. Select where you want to save these images

iPhone 6

1. Create & Save / Open a Saved Sketch file
2. Create a new artboard sized for iPhone 6 @1x
3. Or, select artboards you want to export that are already at that size
4. Click Plugins > Save with Frame > Export iPhone 6 Assets
5. Select the color iPhone you want to frame your artboard
6. Select where you want to save these images

Moto 360

1. Create & Save / Open a Saved Sketch file
2. Create a new artboard sized at 360x360
3. Or, select artboards you want to export that are already at that size
4. Click Plugins > Save with Frame > Export Moto 360 6 Assets
5. Select the color watch you want to frame your artboard
6. Select where you want to save these images

Thanks to

[https://github.com/GeertWille/sketch-export-assets]