We are working on iOS for last 6 years and we have developed more then 50 projects and having some of the clients like Audi , Chevrolet , Jhonson , Parle etc.
We have already developed a similar type of system which can cross communicate from iOS to Android PNS or vice versa.
let us know your interested level and we will come back to you with best quote and complete architecture.
regards
Vinit