Welcome onboard the sofi journey, i hope you have some great sleep in your future too. 
Are these actual pebbles or electronic?
All about them is written in the first pinned thread in the Treehouse. (Index). You can look around there for lots of info but i will attempt to post the link here:
There’s more about the story of the pebbles, I’ll try the link again.
It didnt work, my phone is playing up as well.
Go to the first topic at the top (Treehouse Index). Scroll down to the heading that says something like ’ Got pebbled? The story of the sofi pebble.
Then in there, scroll down to the post by Kaveh and you can find out about the pebbles.
Yes they are real.
I have no idea what an electronic pebble could be!
Thank you so much for sharing our common narrative here @drmudlark … grateful for all the support Sue 
You are welcome kaveh.
I was hoping to post a link to a new pioneer asking about them, with your text about the origin of the pebbles with the pictures (i think it was you, I’m brain fuzzed now!)
But … i couldnt work out how to link to just one post in a thread.
Hopefully they will find it if they scroll down 
You nailed it @drmudlark! Link to the specific section posted above - thank you kindly for the support and sharing the pebble story love! 