I'm still intrigued by the idea of the alarm clock app that doesn't shut up til you scan a particular bar code, for example, your box of tea or the toothpaste in your bathroom.
How could this be recast as positive reinforcement rather than negative reinforcement? One idea: you could subscribe and then there'd be a random chance of "winning" a small gift box when you scan the barcode that's then mailed to you, but that involves both money and a delay.