This extension brings the structure visualizer in the map mode scroll bar back to visual studio 2017. This feature was originally from productivity power tools 2015.
This is an excellent aid for code navigation as you can see the whole structure of your code file in the map mode scroll bar. Each function appears as a coloured semi-ellipse.
I take no credit for this extension it was originally created by dpugh, I only recompiled it for VS2019.