okanatas/NFCCardEmulator — reverse-engineered prompt

Build me an Android app that turns a phone into an NFC smart card emulator so I can test card readers without needing a physical card. I want it to use host based card emulation and make it easy to watch the communication between the reader and the emulated card, so I can verify the reader is sending the right commands and getting the responses I expect.

Please give it a simple, clean interface where I can start and stop emulation, choose or edit a test card profile, and see a live log of requests and responses during a session. If it fits the project, add a simple way to try sample payment style test cases like the Visa and Mastercard examples mentioned in the README.

Keep the app practical for testing and debugging, with clear status messages and an easy way to review what happened in each session. You can look up current Android NFC card emulation docs online if you need to.