Build me an App (database driven)

The App is rather simple.
It is mostly database handling, and searches based on criteria.
The app is to be coded for both Android and iPhones.
Frontend and backend development required.

The App is a sport athlete database (picture, age, weight, height, sport category, sport level, location based on address, ...)
Athletes can do multiple sports. Each athlete can then have a different level of expertise in each sport.
Every athlete belongs to a specific team (each team as 1 Team manager).
Team Managers can then make searches to match their athletes to other team's athletes based on multiple criteria (such as weight, height, level, location ...).
See basic mockups attached.

The app requires login/registration. Registration is when data entry for the database is inputed.
The app has a menu that allows different options and settings, such as adding additional athletes in the team or adding missing information.

A more detailed and complete mock up, as well as additional information will be shared with the freelancer we will hire.

Please provide a quote and advise what languages you plan on using for the database implementation and for the app development