Several online sports betting companies saw their stock values climb Thursday, including DraftKings (DKNG 2.79%) and Penn National Gaming, after Reuters discovered and revealed changes made to Google's (GOOG -0.21%) policies back on Jan. 20. Those policy changes will enable companies to place gambling apps, including sports betting apps, on the Google Play store available to U.S. users.

DraftKings is preparing to pounce on the opportunity, according to a report by 9to5Google. Up until this point, DraftKings' Sportsbook & Casino app has not been available through Google Play, though it has been through Apple's App Store, among other channels. However, on March 1, Google says companies in "Australia, Belgium, Canada, Colombia, Denmark, Finland, Germany, Japan, Mexico, New Zealand, Norway, Romania, Spain, Sweden, and the United States" can also list betting apps on Google Play.

App icons floating above a smartphone lying on a wooden tabletop.

Image source: Getty Images.

DraftKings says it will have its app listed and available on Google Play immediately after the rule change is implemented. Currently, only the Google Play stores in Ireland, France, the United Kingdom, and Brazil allow gambling apps to be listed. DraftKings' app, like all similar apps that will appear on the U.S. Play store, will need to be free in order to qualify, and will be listed as Adults Only, the most restrictive of the five ratings under which Google classifies apps.

DraftKings has continued to expand the availability of its sports betting services as legalization continues its march across the country. The company added its 12th state this week with its launch in Virginia. The company is also drawing strongly bullish ratings from some analysts who believe it still has plenty of upside as more states approve its style of gambling.