This is looking very very good. I encourage you to continue working on it, but focus on completing most important elements first. And I'd suggest you'd release it as standalone, with exporters, as not everyone is using unity, and I'd buy it for sure. GL
Hi Mikolaj, thanks for the kind words! My goal with Mesh Edit is to make a modelling and texturing tool that runs inside Unity, so I don't think I'll ever have a version that runs standalone. If you're looking for a standalone application, some great alternatives are Sprytile and Crocotile.