SkinToolsEnv
This is a new version of the skintoolsenv that is has been available for some years now - it can save large amounts of time when setting up skinned characters.
New features include a reworked UI allowing finer control over start/middle/end envelope crosssections with modify value by absolute/relative/percent - the ability to rotate indvidual bones (very useful for when they initialise in the wrong orientation) - an assign skin feature which allows you to set the initialisation parameters - dockability - compact floaters for all and selected bone controls - choice of axis for the move crosssection end mode - and a replace bone feature which allows you to replace an existing bone in your rig with an object not currently in the rig while maintaining the enveloping and weighting.
After running the script in the downloadable zip file you can find it in the 'RPManager' category of your customise UI controls. Note that you need to have a skin modifier active in the modify panel - and if this tool was already open have used the 'rebuild Selection Sets/Bones' button to initialise the script properly.