APP for Restaurant reservation - FOR ANDROID and iOS

We need an app for the management of restaurants and bars that allows you to book, order food and drinks, and notify the kitchen of what has been ordered. The backend is ready and the tests can be started immediately. We are therefore only interested in developing the frontend. 1. We are interested in a programmer with experience with push notifications and the GCM/FCM., available for debugging and with good problem solving skills. We must be given the user and password with which the project will be registered on GCM / FCM as well as the exact link to access it. 2. The ideal person for this project is a collaborative person, whose purpose is to solve problems in order to reach the conclusion of the project in the best way. For us, human capital is extremely important. 3. The app must be developed both, for android and iphone, with free or open source products and any libraries used must also be free. The source files must be compilable by us in order to obtain the apk/ipa. You will therefore have to give us all the instructions and support for the compilation. 4. We pay the agreed amount only at the end of the project, when all the frontend functions that we have requested are correct and functional, not step by step, with only one milestone at the end of the project. We will not accept upward offers. 5. the development will have to be done step by step, and you will be able to move on to the next step only if the previous step is completed and functional. 6. The communication between frontend and backend must take place via https/post and the backend responses will be in json format with OK or KO as well as a return code and a description in the 4 supported languages: Italian, French, Spanish and English. 7. The app, depending on the language of the smartphone, will have to set the language in which to propose the screens, between Italian, French, Spanish and English. If the language of the smartphone is different, you must choose English