Automatic area code match with a city and province

Hello. This project has to do with function and not any design. You can do whatever preliminary design that's necessary. We are focused on function. And only front-end. We are looking for an android developer who can create the following: Create 1 UI slide where you can select any country in the world via a drop down list where the area code and flag of the country are beside the country name. You can most likely find an open source code as such. In fact we have one and we can give you in which there is a code on its own, in which when you select a country, all the provinces of the country show up. And when you select a province, all the cities of the province show up. For the whole world and even for the smallest towns. However, we are then concerned with the area code. And thus we want it the reverse way. In that, when a country is selected, we know the COUNTRY code. Then if the user enters a city code (for example 250 in North America), not only the code automatically detects the city, but of course also the province of that city. This will allow the user to SKIP the step of entering city and province by automatically detecting those via the phone area code. We want this done for android for this project. if it goes well, we would need it for iOS as well if the freelancer wishes to do a subsequent same project for iOS. We want these area code matches for every province and city in the world. But especially for North America. Thanks.