Write an Android application

Need to create a demo app for client Requirements: - explain to me Android app creation process - build demo app according to my design, will only have 1 main page at this stage and 2 simple sub pages - the app needs to scan QR code, please only apply if you have experience working with an opensource scanner software The app will require additional work after client approval and will need to be created for iOS so experience is a must. Expected budget for this initial demo app is $50-60, please send comments if you feel otherwise.