1. Register your videos and images with the USCO. It'll cost 2. You can now file DMCA takedowns. Send one to Apple with the USCO registration ID and a copy of the image and a link to the app in question.
3. Apple will either immediately remove that fake app, or be liable for up to $350k in punitive damages for wilful infringement and lose all DMCA protection.
4. If Apple didn't react a week later, approach a lawyer. They'll likely be willing to work purely for 50% commission, because it'll be a slam dunk in court.
5. Repeat the same with Facebook / Youtube if they advertise there with your images or videos. Take Screenshots and write down the url and date and time.
Of course, one would hope that Apple will do the right thing, but it's also reasonably easy to force their hand.
That said, I don't know anyone for whom app development worked out financially if you fairly price your own labor. So maybe just stay away from cheap apps in general.