I’ve been practicing a couple of months with the tuner in front of me. I practice scales with the tuner. Of course I do not just watch the tuner, I also try to listen very carefully. When I play etudes and pieces the tuner is in front of me too. I think it helped me really well to find out which notes I systematically play wrong. And I did notice that lately I don’t watch the tuner so much anymore but I do start to hear when a note is the right pitch and when not. So, if I remove the tuner now, I can still play in tune. 🙂 In my case it was/is very helpful, but I’m glad that I don’t depend so much of the tuner anymore now.