Apple lets developers generate 50 promo codes so they can give out their paid apps for free. Developers can use these for reviewers or to get some good PR on Twitter. Apple made it really easy to redeem the codes by making it possible to embed them in a URL that will open up iTunes and take you right to the page to redeem it for you.
Lots of people don’t know that you can do this with promo codes and URLs. I’m not sure who figured it out, but it seems like Tap Tap Tap was the first to figure it out. One problem with this is that once someone clicks the link and redeems the code, it’s invalid. So only the first person to click the link gets it, otherwise they get a dead link that shows you an error message in iTunes.
So I tried to solve those problems with my App Store Promo URL Generator. It lets you paste in your App ID and some promo codes and it will generate a URL you can use to share multiple promo codes with one link.
It works by using your App ID as a key to pull out a promo code from the list you entered. It will pull a new code from the database until it runs out. When it is out of promo codes, instead of getting an error message, you will be redirected to the apps page in the App Store.
I threw this together using the Twitter bootstrap page template to make it look nice. I used some simple php and MySQL to take care of the rest.
I hope you find it useful and would appreciate any feedback you have.