iOS Developer for app customization for tablet UI/UX

The client is looking for a developer to update an existing iOS app, which was developed for small screens, to work well on tablets. Concept and design have already been created by the client.
Very important to the client is that the developer has good knowledge of the architecture of Swift apps.
The customer, for which the app was created, is based in south of Germany, and the freelancer should be able to work onsite at the customer's office for one week at the beginning of the project.
The developer will work in a team with another iOS developer and a tech lead.