QR Visitor management mobile app

I need an iPhone and Android app. I would like it designed and built.

The app will be tenants and visitor management system using QR code.

The backend should support multiple customers to have their own work space to add their sub-customers so sub-customers can app the users as subscription such as tenants, employees, visitors etc.

For the mobile app every user such as tenants, employees, visitors etc. will have a registered account and profile.

The profile will show a QR code to identify this user.

The integration will be done by REST APIs with access controller.

The solution should be cloud and local hosted.

The advantage for whom who have similar projects with proof.

Source code should be included, and support SLA will be agreed.

Regards.