Comment by kaibee

I'm less likely to commit to using something if I'm going to have to decide to pay for it sooner. I would try offering a month or two free and see how many people commit to using it and over what timeframe. You probably want people to be invested in the app, such that it becomes worth it for them to pay because it would be cogitatively expensive to switch. A week is definitely not enough time to build that kind of habit.