Sounds ambitious! What are the key challenges for you? Are you able to develop the product yourself, and just looking for ideas of how to grow it to millions of users? Or do you need to find people to build the product/app itself? There are lots of resources available for both.
Have you created a prototype? - sometimes mocking up a product will yield little by little the needs you would face as business and potential channels for fulfilling those needs, not to say that need could lead you to just the right person.
Give one of us a call to bounce ideas and help you curate your thoughts and find ways to claim the market.
If you are looking to add something to every cell phone you need to think through what is the value for the gatekeeper (OEM or Carrier) Typically the OEM (HTC, Samsung) or the carrier (Sprint, Verizon) will have to be pursued to add the application / link and either wants upfront payment to do so or back end dollars from conversion. I spent many years working on getting mobile applications onto devices both at the OEM level as well as within a retail environment from within a fortune 100 retailer. Its is not just about having a great idea but making the idea appealing to all parties involved - OEM, Carrier, Retailer end user.