"Today after 12 o'clock in the day (10:00 GMT) a message comes up on the screen when installing a mobile application from the PlayMarket shop from a Crimean account: 'Unable to download application due to error 403.' Error 403 means that access is denied. The application still works for users of two-three Crimean providers," Yakushechkin said.
Earlier in January, Google's AdSense system notified users registered in Crimea that their accounts would be blocked.
Earlier this month, the US-based companies PayPal and Apple announced that they would suspend services in Crimea, while last December the US payment giants MasterCard and Visa suspended services to banks in Crimea.
US companies have ceased business activities in the peninsula in the wake of an order issued by US President Barack Obama on December 19, 2014.
The restrictions, specifically targeting Crimea, were imposed by Western countries after Crimea's reunification with Russia in March 2014.