Screenshots
First screenshot

Multiply blending mode
GSI standard map is blended with shaded relief map
Add layer dialog

Measure tool (area)

Measure tool (length) with Measure (Vincenty formula) plugin.
Available in Experimental project.
Slope map created from GSI elevation tile
Available in Experimental project.
3D Viewer (three.js) - 3D steep slope map
Steep slope map was created from GSI elevation tile.
Sources: GSI standard map and GSI elevation tIle.
3D Viewer (three.js) on iPad
Sources: GSI standard map, shaded relief map and GSI elevation tIle.
iPad2 (iOS 9.1)