Several popular iOS games and apps have had their price reduced to zero.
The promotion is not formally explained anywhere on Apple's website, but The Verge says it could be related to the App Store's 5th anniversary.
The list of free apps includes Traktor DJ, Day One, Over and Barefoot World Atlas.
Free games include Infinity Blade II, Badland, Tiny Wings, Where's My Water? and Superbrothers: Sword and Sworcery EP.
For comparison, the standard price for Infinity Blade II is $6.99, while Traktor DJ for iPad goes for $19.99.
We're waiting for an official explanation from Apple regarding these discounts, but in the meantime, we recommend you go and treat yourself to some freebies.
Update: Apple's promotion for the fifth anniversary of the App Store is now live, listing the apps that have been discounted along with an App Store timeline. You can view the promo in iTunes or on any iOS device.