On a bone stock iPhone, the Messages app sports a plain background — either black when using dark mode or white when using light mode. If you’ve ever craved something with a bit more pizzazz than that, then you’d be out of luck.
Fortunately for jailbreakers, running a bone-stock setup isn’t necessary, and a newly released and free jailbreak tweak named ChatWall by iOS developer Chr1s offers an effective way to change the Messages app’s background to virtually anything you want.