Blender – Weight Paint Tools v2.1.7

Addon for Blender 2.9 and 3.x containing tools for simplifying workflow in blender weight paint mode. Useful for riggers, animators and character artist but not only.

easy menu for applying weights to vertices - with properly working symmetry and auto normalization
custom weights mirroring for all tools, works even if topology is not symmetrical.
symmetrize vertex groups that works even if topology is not symmetrical
easy picking/copying vertex weights, from multiple selected vertices.
mixing vertex weights - add, replace, multiply weights from one bone to another
improved smoothing, level weights - with properly working symmetry and auto normalization
draw gradient with custom gradient falloffs (Ease, linear, Gaussian), and mirroring.
'Override from adjacent' - replace broken weights on selected vertices from adjacent geometry.
Project weights - Project weights from non selected mesh parts to selection

https://bartoszstyperek.gumroad.com/l/weight_paint_tools