Unity Assets
https://assetstore.unity.com
https://assetstore.unity.com/lists/top-free-packages-13201
https://github.com/michidk/Unity-Script-Collection
Playerprefs (Free)
https://www.assetstore.unity3d.com/en/#!/content/26656
Inputs
CN Controls
https://www.assetstore.unity3d.com/en/#!/content/15233
Free
2d Animation
https://www.assetstore.unity3d.com/en/#!/content/79840
Screenshot:
https://assetstore.unity.com/packages/tools/instant-screenshot-24122
Shaders
Vertex Paint
https://github.com/slipster216/VertexPaint
Package Uninstaller
https://www.assetstore.unity3d.com/en/#!/content/35439
Save
https://www.assetstore.unity3d.com/en/#!/content/57432
Curved Text
https://www.youtube.com/watch?v=NPylGGZdGPc
https://github.com/PushyPixels/BreakfastWithUnity/tree/master/Assets
Miniprofiler
https://assetstore.unity.com/packages/tools/mini-profiler-32042
Unity Effects
https://github.com/PushyPixels/Unity5Effects
https://github.com/PushyPixels/KvantSpray
https://github.com/PushyPixels/KvantWall
https://github.com/PushyPixels/KvantSwarm
https://github.com/PushyPixels/KinoGlitch
https://github.com/PushyPixels/KvantLattice
Runtime Inspector & Hierarchy (Free)
https://www.assetstore.unity3d.com/en/?stay#!/content/111349
SceneMocap (Free)
https://www.assetstore.unity3d.com/en/?stay#!/content/109683
Game Jolt API (Free)
https://www.assetstore.unity3d.com/en/?stay#!/content/103938
Breakable Windows (Free)
https://www.assetstore.unity3d.com/en/?stay#!/content/110383
The Great Fleece (Free)
https://www.assetstore.unity3d.com/en/?stay#!/content/110186
Daily Rewards - Free
https://www.assetstore.unity3d.com/en/?stay#!/content/110798
Simple City Builder (Free)
https://www.assetstore.unity3d.com/en/?stay#!/content/108619
Free Horror Game Kit (Free)
https://www.assetstore.unity3d.com/en/?stay#!/content/108847
WaveformProvider (Free)
https://www.assetstore.unity3d.com/en/?stay#!/content/109659
Manoeuvre FPS FREE
https://www.assetstore.unity3d.com/en/?stay#!/content/109348
References
http://www.androidnames.com/development/best-unitys-free-assets/
https://github.com/RyanNielson/awesome-unity/blob/master/README.md#ui%22
5 Assets to Boost Your Productivity in Unity:
https://www.youtube.com/watch?v=qfK1eLLVWVE
Player Prefs (Free)
https://www.assetstore.unity3d.com/en/#!/content/26656
Inputs
CN Controls
https://www.assetstore.unity3d.com/en/#!/content/15233
Free
2d Animation
https://www.assetstore.unity3d.com/en/#!/content/79840
Shaders
Vertex Paint
https://github.com/slipster216/VertexPaint
Package Uninstaller
https://www.assetstore.unity3d.com/en/#!/content/35439
Save
https://www.assetstore.unity3d.com/en/#!/content/57432
http://www.androidnames.com/development/best-unitys-free-assets/