Picker Builder 
Before purchase this is a limited version. You can build pickers 10 times.
Picker Viewer 
It is free ! (for animators) You can edit an already existing picker in it.
support Maya versions: 2014-2024
How to install: Unzip and drag and drop the install.mel file from unzipped folder( not from zip) into Maya viewport.
Or download installer from Autodesk (ver 1.390):
After installation, restart the Maya and Picker Builder will appear on the menu
Examples:
Load rig as reference and press on shelf. Pickers are already included in the Picker Builder
Mery
Rig by: meryproject
Rig: download