Hi folks!
We’re an early stage startup in Berlin building an embedded wallet for IoT devices. We’ve done some prototyping on Photon during the last few weeks and would like to share our results with you. I’ve written a blog post with more details about the whole thing: https://medium.com/@bdjukic/building-embedded-wallet-for-ethereum-c9777c1f4697. Hope you’ll enjoy it as much as I did working on it 
Btw, I’ve published a library embedded-ethereum-wallet which you can use now to do your own IoT-blockchain projects.
Cheers!
Bogdan