When I quit smoking 35 years ago I used a lot of little gimmicks that were helpful. I made a little booklet and listed every reason I wanted to quit, then put the book in the same pocket where I kept my cigarettes. I sucked on lollipops, and once in a while I would push in the cigarette lighter of my car and absent-mindedly start to light the end of a lollipop stick. If there were apps and patches in those days, I would probably have used them.
Ultimately, it takes a lot of willpower and discipline. No app or gimmick can replace that, but anything that promotes quitting (shy of the government forcing everyone to do it) is a good thing.