AssetStudio

AssetStudio offers a free and convenient library management environment for all your Unity assets, both individual objects, and complex folders, containing various components and textures.

AssetStudio is a program with a self-explanatory name. The open-source project is free of cost, and it is not affiliated with Unity in any way. However, it targets Unity users who have a bunch of assets and instruments that they need to organize comprehensively.

The application is comfortable because after importing your contents into it, you can arrange your assets by name, container, or type, visually sort the files hierarchically, or simply implement a class organization method for your files.

At the same time, you can use this tool for organizing the content by the Unity version they relate to, export your contents in a split/merge way (and include or exclude AnimateClips), as well as granularly, configure the exporting parameters, file formats, or simply generate XML reports with your assets (details included) — all of them, filtered sections, or partially.

Using this program, you can add various file types into your working environment. For example, AssetStudio supports the addition of 2D and 3D pieces, such as texture types, fonts (TTF, OTF), Text or Movie Assets, animator pieces (FBX files), AudioClips (MP3, OGG, WAV, M4A, FSB, etc.), as well as Sprite files (cropped pieces of Texture2D into PNG, TGA, JPEG, BMP).

To conclude, the current application is a valuable asset for any animator's and video editor's toolkit. Also, regardless of your skill levels and animation creation techniques, the app can be used by beginner and advanced users, for helping accurately sort, manage, and organize your Unity assets.