Q: App issues

You don't have access to any computer with iTunes on it, no friend or family member ? That is the only way to properly see what is owed : Pay an unpaid balance in the iTunes Store - Apple Support

But it's likely to be your last purchase, you can view (and optionally contact iTunes Support if you have a problem with a purchase) your last 90 days purchases via http://reportaproblem.apple.com

(Until what is owed you won't be able to download anything else, including free items, updates to apps, and redownloading past purchases.)