This is very easy although very dificult to find. At least for me.
I wanted that every time I restart Ubuntu, It would have the applications I left open. But I didn't know how to do it. So what I looked for is to initialize some apps. that I have choosen at the startup. I found after many hours of search and reading this link:
And it's just so easy.
- Go to System > Preferences > Sessions (most people know what to do when they get here, the problem is just to get ) - At the startup tab just include your program and be happy
After this, I also discovered the option "Save sessions changes automatically", or smth. like that, under the first tab, "Session Options". Select it to mantain apps. you have opened in your section and changes you have done.
Very handful to gdesklet soft that I don't need to start every time I turn on my pc.