Jack Underwood is bringing a really sweet application to the Android ecosystem, the ability to get promo codes for free, high quality apps!
This has all been possible with the introduction that Google made a little while ago, allowing developers to create promo codes for their software, which in turn would allow users to get access paid application for free. The idea was to streamline the process and make it easier for developers to market themselves out there by giving the chance to some lucky people.
By pressing "I'm feeling lucky" you have a chance at winning a promo code. If you do, you’ll get a promo code which you can enter in the Redeem section of the Play Store’s nav drawer. If you don’t win you will be booted to the featured app’s normal Play Store listing with a “better luck tomorrow” message.
Something to also consider, you can only try this once per day. Take a good look at the Com Back Tomorrow message, you can if you choose to, to follow them on Twitter for more chances of getting some promo codes.