Actively maintained/updated - very nice!
Both this app and the Qingping Air Monitor Lite get frequent software/firmware updates and new functionality is added. I will begin recommending this product to friends! It would be a nice addition to get a warning when any of the levels “jump”/change a lot. I would also like to figure out how to put it in standby to save battery when not used and not plugged in to power - when traveling I could then turn it on temporarily to check current levels :)