I have one of these. The sous vide cooker itself is very nice and easy to use, I’d highly recommend it. The app is a bit clunky and not necessary to use the device. I certainly wouldn’t pay $2 a month for it.

The app lets you set a temperature and cook time, but you can also do this using the buttons on the cooker. Sometimes the WiFi pairing is finicky, so honestly I skip the app half the time. The app also lets you view and write recipes. I guess the big advantage is you can click “start cooking” and it automatically sets the device temp and time, but doing it manually isn’t much harder. I’m also not wowed by the in-app recipe selection, and generally just get recipes from the internet.