Ultimate Voxel Optimizer for Unity is now released and on sale for two weeks! This includes ALL of the UVO source code, so you can optimize your meshes in realtime! Asset store
Mesh Optimizer | Modeling | Unity Asset Store
05 Unity3D Menu – optimize mesh instances | Edy's Projects
Optimization: Mesh Settings – Shahbaz Sekhon
WIP] Tight Mesh Sprites - Configurable and Optimized - Unity Forum
Unity - Manual: Compressing mesh data
Optimization Tools for Unity
Modelling | Free Full-Text | Improving Mobile Game Performance with Basic Optimization Techniques in Unity
Generating meshes procedurally in Unity – code-spot