So it can notify you when the water has reached the set temperature or the time you set for cooking is up. Which can be handy. However, I found the BT very weak on my Anova and it would lose connection when I went into my home office a mere 25’ away, so I stopped using it. There’s actually no need for the water to be up to temperature before you put your food in, and food can sit as long as you want; half the point of sous vide is to be able to hold food at temp without overcooking. So you don’t really need the timer either.
So it can notify you when the water has reached the set temperature or the time you set for cooking is up. Which can be handy. However, I found the BT very weak on my Anova and it would lose connection when I went into my home office a mere 25’ away, so I stopped using it. There’s actually no need for the water to be up to temperature before you put your food in, and food can sit as long as you want; half the point of sous vide is to be able to hold food at temp without overcooking. So you don’t really need the timer either.