Available at https://assetstore.unity.com/packages/tools/animation/dynamic-bone-16743
Dynamic bone will add physics on bones based on your configured settings. This can apply advanced movements to for example hairs, a skirt or something like that.
Available at https://assetstore.unity.com/packages/tools/animation/final-ik-14290
Final IK is a inversed kinematics solution for all kinds of rig structures. For detailed information visit the asset store page.
Available in the Unity Package Manager
PPS v2 is used to add post processing effects to worlds based on the players location. It is commonly used for effects like Bloom, Color grading and more.
Available at https://assetstore.unity.com/packages/tools/particles-effects/aura-2-volumetric-lighting-fog-137148
Aura is a collection of tools to generate stunning visual effects for a world.
Available at https://assetstore.unity.com/packages/tools/particles-effects/aquas-2020-138749
Aquas is a water shader and script collection made to enhace the look and feel of worlds by adding realistic water.
Available at https://assetstore.unity.com/packages/tools/terrain/r-a-m-2019-river-auto-material-2019-145937
RAM 2019 is mostly used to easily create and modify realistic rivers for worlds.
Available at https://assetstore.unity.com/packages/tools/terrain/cts-2019-complete-terrain-shader-140806
CTS 2019 enhaces the Unity Terrain by providing a way to change and recolor / retexture the unity terrain on the fly and giving advanced tools to enhance the look of worlds.