I would like to hire an App Designer

We are looking to create an app for our mobile beauty business. The app needs to be simple, easy to use, girly and fresh. Customers will browse the app, select a treatment of their choice and pay for it through the app. A mobile therapist will then be sent to their home to carry out the treatment. The app must have some sort of tracking service, to guarantee therapist safety. Through the app, the therapist must be able to notify us of their arrival at destination, start and Finnish of the particular treatment and the time of departure from the job. We would like to be able to add regular newsletters and possibly videos to the app. A link to all social media sites, and possibly a customer service feature. Its important that we can email the customer and send push notifications its also important that we are listed on the App Store. We would like to know the cost of making the app compatible for smart phones and androids please. We would like to receive a break down of all costs and any advice would be welcome. I hope I have given a rough idea of what we would like and look forward to hearing from you. Thanks Laura