On the other end of the spectrum - if you just want to get photos from a (non-communicating) camera to a smartphone you can always use a WiFi card. No remote control but if you need to send a photo immediately then it's a cheap solution.

I had the case last night. I was with someone who was doing photos in a very dark bar on a Smartphone without flash and the results were - awful. I had the RX100 with me but I had to have the results immediately. I thought about a QX (same internals as the RX100ii) but there are a couple of important drawbacks for doing photos in bars:

- it's not as pocketable as the RX100
- it can't shoot RAW. I can get spectacular results in bars but only if I can rework the image afterwards

Anyway - full credit to Sony for having come up with something imaginative.