The hacked Android Market apps of SnappzMarket and AppBucket.
On Monday, American prosecutors announced that two of the four men involved with two Android piracy sites, snappzmarket.com and appbucket.net, have pleaded guilty to copyright infringement.
The case marks the first time that US authorities have successfully prosecuted a case involving pirate app stores.
The FBI shut down the sites listed above in August 2012 and filed charges against the quartet of men in January 2014.
The two men, Nicholas Anthony Narbone, 26, of Orlando, Florida, and Thomas Allen Dye, 21, of Jacksonville, Florida, pleaded guilty to one count each of conspiracy to commit criminal copyright infringement.
They are set to be sentenced in the coming months.