Geometry Combiner is an advanced combine tool which allows you to make your game twice or three times faster.
What made Geometry Combiner particular is light-map modifier.
Light-map modifier can setup your combine meshes for a correct,neat and fast way to interact with light-mapping.
LOD system identifier is other side of Geometry Combiner this feature can find dynamically LOD, by shortened or symbols in name of game-Object or mesh.
For instance you can put a short name of LOD at front of mesh name and just write it at list in order automatically system will combine them and puts in LOD Group.
Key Features :
-Open Source
-Document Included (Explained Features Completely)
-Easy to Understand And Manipulate
-Multi Material Support
-Can Save Mesh In Project Folder Which Allows You To Use Combined Meshes In Other Scenes
-Advanced Light-map modifier(2UV,LOD light-map,etc)
-LOD Combine (Find The Target LOD Meshes By Symbols Or Shortened Names)

Some additions props to start combine with:
-12 Prefabs
-32 Meshes
-3 Maps (1K)