fuglesang, Now it's works for me! It's very useful, thanks!
But It has problem with session naming in some case For example, 95% of my directory (projects) has same name "site". And this directory placed in directory with true name of the project. Like "Project-1\site", "Project-2\site", "MySite\site" etc. But session name has last folder name: "site", "site", "site" etc
Small update: Made it so the session files are opened based on the path to the .sublime-project file or the directory opened as a project. This resolves the issue with having more projects (or directories) with the same name. Though now you can't move your project around without having to remake the session. Also the old sessions are invalidated and have to me remade.
@jbjornson, tgkeul I'm glad you like it. ^^
@Esente I tried to see if there was anyway I could implement support for this, but I can't find anything that can help me. Doesn't seem like this can happen automatically though I will see a bit more if I can come up with a solution. If you have any ideas on how this could be implemented, please tell.
From the API, I think you can detect all opening windows from Sublime, so I think you could save that info into Session. Next time Sublime is loaded, there is command to open a new window. We could create tabs from that new window based on the info from the Session, no?