Post-processed PRO Outline asset is great for your game if you want draw outline different objects.
Post processing stack v2 and Unity 2018 or higher required.

Features:
- Works with 2 Render Pipelines without additional setup (Built-in, LWRP)
- Easy to use
- Depth Testing
- Blur
- Works in scene view

Options:
- Per-Object Color
- Fill Object Shape
- Depth Culling
- Invert Depth Culling (draw visible part or not visible part)
- Depth Overlap
- Blur Scale, Iterations and Downsample (more soft outline)

* Not tested on mobile and VR platforms.
** No layered outline feature
*** Now doesn't works with PPv3 in HDRP 5.3.1 and greater