Someone could tell me, when the Czech course for cell phone will be available?
Nope. Nobody knows. I am personally not a fan of mobile versions though. Learning on them is easier than on browser version (I know from learning French) and it is has a lot of bugs and false reports telling users something is wrong when it is not. Typically once a course is out of Beta, it gets its mobile version.
You can always do Czech courses via Browser, but, yeah, I was wondering the same.