+1. You can put together a DMCA claim in... maybe five minutes? It's extremely straightforward and doesn't require you to do anything beyond identify the infringing work, identify what work of yours it infringes upon, and affirm that it's not authorized.

Here's a template: https://library.georgetown.edu/copyright/dmca-takedown

I got it removed from the App Store. The first time, then after some months the same developer republished it with a few changes under a different name… I don't have the time to track it down again, I just published my app on the App Store for free so at least people won't give in and avoid the scam.