Can I recover my Mastercoin/Omni asset that I mistakenly sent to a Counterwallet address?

Yes. Please contact your Omniwallet support for instructions on how to do that. Do not share your pass phrases, passwords, or private keys with anyone!

In case you need the private key for your address: access your wallet using Counterwallet, find the address and from drop-down menu above it select Show Private Key (do not share it with anyone).