Product review (5 stars): Accurate, and with a powerful bundled software app.
After downloading the app, this was plug and play with my Samsung Galaxy phones.  It was accurate enough that I had to make sure I wasn't breathing near the sensor as I was affecting both temp and humidity.  There are certainly more budget friendly options out there, but what really impressed me with this one is the app.  Want to track the data for a specific location?  How about view a graph at the push of a button to see historical changes, or attach a photo with datapoionts for easy reference?  The app does all of that and more.  I also liked how easy it was to send/share data with others.