updated 09:33 am EDT, Tue June 3, 2014
New rules simply require compliance with local laws
Apple has quietly changed rules at the App Store to allow for digital currency transactions to take place within apps, Reuters notes. The rules now state that apps "may facilitate transmission of approved virtual currencies provided that they do so in compliance with all state and federal laws for the territories in which the app functions." Apple hasn't identified which currencies it will allow.
Only a handful are in widespread use however, and the most popular of these is Bitcoin, which Apple presumably had in mind. An increasing number of businesses are accepting Bitcoins as payment, even though they're not backed by any central institution and have been the subject of controversy. At times the currency's value can fluctuate wildly, and multiple Bitcoin exchanges have lost substantial sums of money as they work to establish trust and security.
Apple is in the middle of revamping the App Store. Yesterday it announced changes due to take place in the fall, which will add things like bundles, beta testing, trending searches, and preview videos.