“Work Product” shall mean all design and applications... excluding the “Elements”. Developer assigns to Client all right, title and interest in and to the Work Product. “Elements” shall mean Developer’s algorithms, libraries, scripts, user interface and experience designs, architecture, objects, graphic files, [etc.]. The Elements shall remain the sole and exclusive property of Developer; provided that, subject to/upon full and final payment for the Services, Developer grants to Client a royalty-free, nonexclusive, irrevocable, perpetual, worldwide, subliceseable license in and to the Elements to use in connection with the Application.

So we do give up copyright for the application as a whole "Work Product", but retain the copyright for individual components "Elements".

The client is not in a technical space, and quite frankly doesn't know much about software development. We may be pulling a fast one here that other clients would refuse. In any case, it hasn't caused any problems in our working relationship and everyone's happy.