I really like this idea and design, but I think it might be really hard to get people to pay 99 cents for an app that interrupts them... since so many apps do that for free :/
I love the design and all, but the idea behind it doesn't appeal to me at all.
What I need is to focus for hours on a hard problem, because that and only that pushes my mind forward. My mind is already trained to interruptions every few minutes (thanks push notifications, thanks Facebook, thanks e-mail)
This sounds like the opposite.
Disclaimer: I built something to track these interruptions so yeah, I'm crazy about being focused. The app is named Escape: http://focuslist.co/escape/
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