SensorBlue 4+

The ipad version doesn’t display mold risk. My android version does for the same hygrometers. Wish they were ifttt or smart life compatible. That’s what I get. I guess for buy cheap devices.

Works reasonably well for a few sensors, but with three, you have to scroll to go from the first to the last. This is ridiculously slow (iPad air 2, so admittedly not super modern), most of the time just resulting in re-ordering the sensor windows in the list. It shows three significant digits in the reading (so two decimals at single-digit temperatures), which seems a lot when the thermometer promises 0.5°C accuracy. “Calibration” seems to just be a fixed offset, so not really a calibration, but may be better than nothing if it is used predominantly in a narrow temperature range.
I’ve seen it display -1000°C when connectivity to the sensor seemed poor, maybe that’s a defect in the sensor or communication protocol.
Refreshing that you don’t need to give up personal information to use it, kudos (and an extra star) for that.

It still tells the current temp and humidity but the logging feature is all but useless now for me. I don't constantly sync, and only want to see the last couple days or so, so if it's been a week or longer, it takes an absurd amount of time for it to sync.

I don't need that data, but why should it take so long to sync anyway? Timestamp, temp and humidity. Even the full 100 days with worth at a record every ten minutes, even with 100 bytes for each record, that's less than a couple MBs. This should take only a few seconds on bluetooth.