I use three: RedSea ReefDose4, Kamoer X1 pro, Bubble Magus TS1.
ReefDose4 is great with what it can do. However, it does have issues connecting to WiFi (for me).
Kamoer X1 Pro is also very good. The only caveat is that it has continued to run (more than once) when doing a manual addition.
Bubble Magus TS1 is a solid performer. There is no real way to calibrate, just adjust if needed. No WiFi or BT connectivity. This can be seen as good or bad. I like the simplicity and use it as such.