Is it possible to control Caspar rundown from smartphone ?
Anything is possible
There is a way to control CasparCG official client by OSC (search the forum for more info, I never tried it myself) and there are OSC app for smartphones see this for one of them. You should be able to build a control surface with it.
I remembered that back in the days (about 2010) there where a smartphone-app for controlling the casparcg server. So I did a fast google
Since its a iOS-app and I use Android I cant say in which condition it is and how its working with newer versions of the server. But I remember that then when I tested it I though it worked for a skilled user but not as a entry-level client
its called SimpleCaspar and this is the link I found
hope this helped but I still have some memories of some other clients outthere using OSC. So it could be a good thing to try to google that
I also remember that. I once got in contact with Leonedo, after that app was removed from App-Store and he told me, that he stopped developing it.