Big_boy_4005 (Elliott) is using JMRI/CMRI on his huge layout. It works with TMCC, but I don't thing it works with DCS directly, maybe DCS via TMCC? Anyway Elliott talks a bit about using it here and there in his layout build thread. Looks a bit complicated to me. Also, I am not sure there is an ipad (or other tablet) app for this? Elliott was doing his all on a PC.
The Lionel LCS system looks a lot less complicated and I think it would be much easier to get setup and running like you want it to. But, I have no experience with either system. Just DCS and Legacy with their remotes here.