Juice was the clear winner of the experiment
I asked David Freedman, contributing editor for The Atlantic and author of “The Perfected Self,” a cover story for the magazine on B.F. Skinner-nodding apps, whether I was wrong to expect more pressure. Skinner, you may recall, was a famous psychologist who said people could "condition" or change their behavior in the right environment.
“I think what you've experienced is something that is commonly experienced by anyone who adopts a vaguely Skinnerian program,” he said. “We've been sort of led to believe this is invasive and leads to unpleasant regimentation, that it's controlling, that it eats into our freedom and we become robots.” But on the contrary, “these apps are building on how the brain works and taking it on in a useful and advantageous way. When we're reinforced then we end up feeling pretty comfortable with it. But on the other hand, really, this does come down to the execution,” and not every app will deliver.
— Mashable | Jill Krasny