This app can control Mijia Thermo/Higro meters, square version. Such devices are visible on Bluetooth network as LYWSD03MMC. There is Android app for this, but why use Android when you can use Windows? :) And this app has some features not present in official Android app (but, of course, also lacks some of functionalities).

Main functionality of this app is download data from app, and export it. Every measurement, and every hourly statistic downloaded from device, is saved in text file. On desktop, you can access this files clicking on “Explorer” button on MainPage. On phones, these files are created on your SD card, in folder Datalogs\MijiaThermo, subfolders for year and month.
App can work in background, retrieving data every 15, 30 or 60 minutes. This data is then compared with warning and alarm levels, and if such level is crossed, app sends you notification (in form of Toast). As data is stored in Roaming form, one instance of app (e.g., on desktop) can retrieve data, and another instance (e.g., on phone or laptop) can show this data for you.

This app greatly utilizes information from https://github.com/JsBergbau/MiTemperature2 .

If you want some new functionality, or encounter some error, please send me email.