Technology Assignment Agreement
The Copyright Law dictates that the code is owned by the developer as soon as it is ‘fixed in tangible form’. Thus, the copyright is yours as soon as you ‘save’ it. Same goes for all the design and creative content in the app. This is covered under the Technology Assignment Agreement.
Work for Hire
There is a bit of legal and contractual documentation. For instance, Independent Contractor Agreement, Work for Hire agreement, or even Contract for Mobile Application Development Services. Clients would want to sign a work for hire agreement as they want to be the full owners of the app source code as soon as possible.
This contract vastly varies from the one above in the IP provisions; the copyright is not automatically assigned, but instead it is licensed to the client or commissioner for a fee. Licensing allows freelance developers to customize their offering in great length.