How should I monetize this app?
nudge: Go for 1)Have it also set your email client to not receive messages in that time (or close altogether).Your app is then a pretty awesome get-some-damn-work-done distraction-eliminator. You could sell to businesses too (perhaps even more successfully) - teach them about the loss of productivity due to distractions - particularly from email and instant messaging - and sell them your app as a solution.