Mobile App Creation - repost 2

My project is to create a new messaging/chat application. It would be very similar to something like WhatsApp, but with a difference. The idea is that the app only uses pictures. A picture says a thousand words after all. I would also like this to extend to being able to use .gif images if possible. So, what I would like to happen is the sender types into a field their message. For example: 'Hello, how are you?' the app then, using Google Images, returns pictures results relating to the sentence 'Hello, how are you?' - The user can then select one of the images that suits their needs. I think there would also need to be a button that instead of trying to find an image for the whole sentence, it could be broken down into each word, or part sentence. eg 'Hello' and 'How are you?'. For the .gif images, maybe there is another button that would just display .gif's. The receiver then just see's the image that has been sent and can reply in the same way. I have put this as an Android application as that is what I use at the moment, but obviously there would be scope to transfer it to IOS. I have no idea how much something like this would cost to create or how long it would take so I am looking for a developer's input to give me an idea. Thanks everyone. Adam