A pretty simple little script that should be helpful when you’re weight-painting meshes for rigs (or… more to the point, fixing weight paints).
When enabled, you can go to the Properties region of the 3D View and click the “Show Vertex Group Weights” button in the Show Weights panel. This enables an overlay in the 3D View that displays the vertex group assignments and corresponding weights for each selected vertex. A more tabular form of this data also shows in the same panel of the 3D View’s Properties region.
This script requires the most recent bmesh python api. It also borrows some code from Bart Crouch’s old Index Visualiser add-on for the overlay (thanks Crouch!).
Known issue: Updating vertex group information in Edit mode will not update the values in the 3D View. To get these values updated, you must either toggle Edit mode or toggle the Show Vertex Group Weights operator.