We have the RadioHead library working on the Photon / Electron now and that library has support for the NRF24 radios.
Check out this thread: Particle Photon / Electron + RFN95W Long Range Radio
We have the NRF95w radios working on a Photon. I’ve been running a test on a Photon and RFM95 radio communicating with another NRF95w radio for almost a week straight now. So I can confirm the RFM95 radios work just fine.