Andriod iPhone phone privacy app

I am looking to have developed a application similar to the following apps with the intention of selling the app on Google Play and iTunes stores (subscription based). I want the app to have a full trial period (1-2 months) then require a pay subscription. The application will be used to hide contacts and communications with those contacts. For example a user would add a contact to the app and all phone calls, SMS texts, picture messages would all be completely hidden from the phone. The user then would login to the app with a PIN or other security measure to retrieve the communications. I am not looking for something completely new. I want to basically want to take all of the benefits of the current apps and improve upon them in this app. Vault: [login to view URL]?t=W251bGwsMSwyLDEsImNvbS5uZXRxaW4ucHMiXQ.. Secret Phone: [login to view URL] Private Space: [login to view URL] Hide SMS: [login to view URL] Voxer: [login to view URL] The application would need to likely use encryption for picture messages and files the user wishes to save. Ultimately the application needs to be as hidden as possible for the user possibly with the option for the user to change the icon and application name. Message alerts should be either hidden or allow the user to create customized alerts for each contact for example if a SMS text comes from a private contact then the user can setup a customized system alert to display any text he wishes like "This fake-app requires an update." If the user clicks on the alert then they are asked to verify their password to access the message. I will award the project to the company who can be innovative and creative. I am not an expert so I want expert input on how to make this app better than what is available. Also important is someone with good communication skills and a good freelancer reputation.