iPhone proximity sensing

Hello my names Rob, just looking for guidance with an amateur project (I ask if you could bare with my knowledge as it is somewhat limited). The aim is to have an ardiuno uno detect the presence or proximity of an iPhone6s, I imagine this could be achieved with a bluetooth module but Iv never had experience with this area and I’m struggling to find information that isn’t vague. My thinking leans me towards pinging the Phone or something along those lines and also it is somewhat important to keep power consumption in mind - will this be a problem with Bluetooth? are there alternatives? The end goal is to have an ardiuno sense the prescense of an iPhone and that will trigger a button or two. I don’t want to use a phone app (Additionally: Seems there’s some issue with iPhones and the SPP protocol used by the Bluetooh modules, not sure if this is relevant)

Hope Iv covered everything Love to hear what you guys have to say and maybe contributing to the forum here and there in the future myself.
Cheers, Rob.