This is a paid asset, but now you can download Unity Package Asset Index Free.
Detail this asset from Unity Store: Original Link
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:
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.