Thomas Pace, 38, of Oregon City, Oregon, pleaded guilty on Tuesday to one count of conspiring to commit criminal copyright infringement over his activity at Appbucket Group, the U.S. Department of Justice said.
Meanwhile, Kody Peterson, 22, of Clermont, Florida, pleaded guilty on Monday to the same charge over his activity on behalf of SnappzMarket Group, the agency said.
Lawyers for the defendants did not immediately respond to requests for comment.
Two other defendants pleaded guilty to the same charge in March: Nicholas Narbone, of Orlando, Florida, and Thomas Dye, of Jacksonville, Florida.
Prosecutors charged the four defendants in January with conspiring to distribute pirated Android apps without permission from software developers and copyright owners.These charges followed the Justice Department's August 2012 seizure of the website domain names snappzmarket.com, appbucket.net and applanet.net.
Pace, Narbone and Dye were accused of conspiring on behalf of Appbucket from August 2010 to August 2012 to distribute more than 1 million pirated apps worth more than $700,000.
Peterson was accused of involvement in a similar conspiracy for SnappzMarket from May 2011 to August 2012, involving more than 1 million pirated apps worth in excess of $1.7 million.
Pace is scheduled to be sentenced on July 9, while a sentencing date for Peterson has not been set, the Justice Department said.
The cases are both in the U.S. District Court, Northern District of Georgia. They are U.S. v. Peterson, No. 14-cr-00025; and U.S. v. Pace et al, No. 14-cr-00026.© Thomson Reuters 2014