[RCD] What can be reached, changing skin?

I wasn't engaged in development of skins for RC yet. Before being engaged in it, I would like to understand what results can be received.

Whether it is possible to change configuration of the screen? To make RC more convenient for operation from the smartphone?

It seems, someone advertized the paid skins intended for this purpose. So it is possible?

And maybe, the decision of this task already exists? I know the program RoundCube for Android which not bad adapts the interface. Though it is not absolutely correct. And for iOS such program is?