Product itself is a nice design; ESP8266 and USB-to-serial converter work flawlessly. Device has three temperature sensor and one humidity sensor and barometric pressure sensor. Designer, from past experience it appears, creates somewhat of a thermal break on the board to ensure that the heat generated by the processor/power supplies has more limited affect on the temperature sensors.

The data is output via push (I didn't test this) or pull and it output in JSON format. Output of temperature can be selected to be F or C. Barometric pressure is only available in kPA. JSON doesn't provide you the units of the temp, perhaps that can be added in a later iteration. No clock is time/date setting is provided, but an "uptime" counter is provided to at least determine delta-time. ESP8266 compatible ntp clients exist, and even the http headers can be used for extracting/setting time, but the function doesn't exist.

I didn't try the self-hotspot wireless setup method; I used the serial port method. The serial interface is a little clunky but functional. Command processing looks at the first letter and then sometimes goes right into accepting the argument. Not totally clear from the documentation, but he said he was going to look at clarifying that. SSIDs can be scanned by the device, which is helpful when selecting the strongest AP, but you must enter the SSID manually rather than selecting the numerical number of the AP listed.

The product also provide a web-page based interface for configuration and displaying data. It appears to work in a reasonable manner, and the graphing capability is cool, if limited in actual utility. Graphing uses the dygraph open source javascript capability internally -- but note the parameters cannot be changed.

Where this product is disappointing is outside of the promised capability. My disappointment is in things the maker didn't promise, but I do want to make sure others here on Tindie are aware. When I looked at the photos here on tindie, I saw additional unused pins being brought to the PCB. I had plans to use those pins for other sensors and indicators. I learned my lesson than Tindie doesn't mean open source SW or open source hardware. I need to do a a little cost-benefit-analysis of whether I should develop an open-source version of the software or look at getting the functionality via other means.

My wish list for this or another product: Basic time maintenance via NTP; ability to push (not just via http client call) but via a basic socket call to a hostname/port the json or CSV stream; some basic LED functionality that can be used to determine if the system is up and online (think a heartbeat blink, an error flash notation, etc)

Bottom line: Good product for exactly what it is promised to be; If you have visions of using this as a springboard for further development, look elsewhere or be willing to re-implement the firmware.

Edit: I've built a case for this device and it can be found on Thingiverse with a CC license:
https://www.thingiverse.com/thing:2519424

I bought two sensors and I got them only a few (four) days after ordering. Not bad for shipping from the US to Europe :-)
After testing I had a minor problem (the graph feature was not working). The Store Owner quickly provided a new firmware and everything was working fine.
The product quality is very good and the configuration was easy.
Thanks for a great product and a great support too!