Anything is possible with accesories but that breaks the thesis.

For the moment, yes. But in practice, this years dongles are next years built-ins. The same was the case with GPS, accelerometers, temp and humidity sensors, blood oxygen sensors, incident light detection, finger print reading, cameras and so on. Phones absorb sensors like toddlers consume cookies, they can't get enough of them.

I’d like to have a thermometer in my iPhone, for ambient temp, but most of all I am waiting for IR photography and the the inevitable calibrated fever thermometer app.

The promo image for the next Apple event looks kinda like IR false colour to me, so maybe you’ll get your wish?

I'll bet $20 you can find a combination thermometer cellphone on aliexpress.

Oh, I found one already!

I don’t want an Aliexpress phone, though.

I have this absurd vision of someone sticking their smartphone edge-on into a slab of beef as a meat thermometer.

I wish that Apple would match all these sensor features on their laptops as well.

I want to those things. Tricorder please.

It will happen. The bigger obstacle is to make sensors cheaper. But MEMS has opened many doors already and I think microfluidics and various gas sensors (think chromatograph in your pocket) will be the next frontier.

SDR++ app enables this on Android