This is a paid asset, but now you can download Unity Package Asset Index for FREE, Please keep in mind this package is provided only for learning purposes or to be able to test before buying the product, NOT FOR COMMERCIAL PURPOSES.
For more detail this asset from the Unity Asset Store: Click Here
Unity Package Asset Index
“If possible, please buy the package to support the developer”
Does not require Unity PRO license!!!
Now includes dependency checking on Asset Import and Package Scanning!!!
This is a utility (currently Windows ONLY) that enables you to search for all Assets included within the Package Files that reside in the Asset Store folder for Unity. You do not have to import the Packages, in order to be able to index/search them!!!!!
This is a system that uses a Lucene index, to store key data of all of the assets that reside in your your Unity Package files. All scanning is done on the Unity Package file itself, and does not require the package to be physically imported into the unity Editor
The following OpenSource Projects are also included, in compiled form only, at the moment:
AudioToolsLibrary.Net v1.2.0
Lucene.Net v3.0.3
Netwonsoft.Json v7.0
SharpCompress v0.12.2
YamlDotNet v3.8.0
These are only included for support of the UPAI, and only intended to be used as Editor only assemblies, and will not deploy as part of a build, due to being marked editor only.