Ever dreamed of having your own large field of view (FOV) AR headset. It might be easier than you think. Come, join the community and build your own version with its own interaction purpose.

He told me that he had a temperature measuring device, that he could not find, back in 2011
He needed something like a data logger. Easy and light, cheap, with a battery lasting over year or so, that he could install at customers' places in order to have a Log of "what happened" if any problem came up.
Say, a frozen (broken) pipe or other malfunctions in heating, AC and such. He said connectivity wasn't necessary and to log to a SD-card that could be inspected later would be sufficient.