Whatsapp hidden / encrypted apps

Looking for someone who can create apps in android and apple store related to whatsapp. Wihtin whatapps content / chat history, i would like to block / hide certain message from the list : provided if user are looking to unblock / view the message : password will be needed. Criteria on this project : encrytion should be placed for this hidden messages so that even if the db of whatapps being transferred to another phone, they are still hidden / encrypted unless your application is there to unblock it Interface should be simple and if possible, do have it in both version apple store and google play ( for iphone and android) please bid if you are well aware of this project and pm me your understanding on this project. Otherwise, i wont entertain this :) thankyou