Ouch, shade on the SensorPush. I had 2 and I got 2 more. It requires an app, but they're quite well made imho.
But yes, open source would be better. If physical portability is not a requirement, Xiaomi hygrometer 2 with this custom firmware https://github.com/atc1441/atc_MiThermometer is quite excellent
But yes, open source would be better. If physical portability is not a requirement, Xiaomi hygrometer 2 with this custom firmware https://github.com/atc1441/atc_MiThermometer is quite excellent