For anyone who has not done this yet...

Source: Digital Trends

Heads up, PlayStation Vita owners: Sony’s PlayStation Mobile service is shutting down on July 15, ending support for a large number of games on the PlayStation Network. Sony has issued a series of steps users can follow to ensure that their downloaded games remain activated and playable for the foreseeable future.
In order to ensure continued PlayStation Mobile game compatibility, PlayStation Vita and PlayStation TV owners must enable an option within their device’s “Settings” app. From there, navigate through “PlayStation Network,” “System Activation,” “PlayStation Mobile,” and “Activate.” Enable the option here and your downloaded games will still be playable after tomorrow’s shutdown.
In order to ensure continued PlayStation Mobile game compatibility, PlayStation Vita and PlayStation TV owners must enable an option within their device’s “Settings” app. From there, navigate through “PlayStation Network,” “System Activation,” “PlayStation Mobile,” and “Activate.” Enable the option here and your downloaded games will still be playable after tomorrow’s shutdown.