Its not an app, its a feature of GrapheneOS. The most secure mobile os, sadly it only supports Google pixels, but for good reason. Pixels are the only android phones with hardware features up to their security standards.
Highly recommend GrapheneOS, been running it for years, gets Google out of all your personal data as well.
Imo, there is a material difference between vibe code and LLM assisted code. Vibe code would be somebody like me with pretty much no coding experience making an end product. And LLM assisted coding would be a real coder who knows what they're doing who uses LLMs for assistance and fully reviews the code.
Whether it's disclosed or not, I am of the belief that pretty much every single piece of open source (and closed) software that is even a little bit popular most likely has LLM assisted code. So theres no avoiding that.