Dien lays of the options as I think of it as well. The only clarity I would add is you could do this one of two ways: 1) specify a domain as Dien describes or 2) create an accountability for mobile developer as Dien described in his last sentence.
Personally, I try to avoid domains where I can because they are such a heavy tool (use accountabilities instead) and they can be abused to make things feel too much like command-and-control. However, domains may be necessary and can be an efficient way to convey needs to more of the organization.
If it makes sense, you may start with some linked accountabilities and see if that resolves the tension.