I've quit smoking a couple of months ago, to be exact: 7M 8d and 9h, according to the app :-) This app gives you the little pad on the back when you need it.
What worked for me was simply to check the amount of money I've saved, when I had a difficult moment. But also checking how your health improved so far was a great help.
I've checked and used other apps. But this one worked for me by far the best.
Tells you to the second how long you haven’t smoked for, gives you badges which help keep you motivated, avalible on iPhone and iwatch