The whole thing (including the toolchain) needs to be open source though for it to be trusted, not sure how Adobe stuff works on that front. And you'll need code of your own to keep the balance updated, load the transaction list etc.

I've been tinkering with the Electrum-DRK client as it's in python (I can read c++ but I wouldn't trust myself to write it) but it uses a different backend (node.js or something I believe) so I'm kind of stuck between learning c++ properly to help with the official wallet, learning js from scratch to help with the electrum wallet, or doing my own thing...