What is PlayStation Mobile
PlayStation Mobile was a software framework that could run games that were cross-compatible with PlayStation Vita and some select Sony-made Android devices (it was later hacked to run on all Android devices). The service was started on October 3rd, 2012, and it ran until July 16th, 2015.
The applications were programmed in C# and ran in a Mono VM. Unlike the PSVita, however, it was an open platform where anyone could sign up and create games for the PSM and have it published on the PlayStation Store for Vita and Android users to play.
When the PlayStation Store page for PlayStation Mobile was taken offline, Sony ended the ability to download PSM games via the download list on September 10th, 2015. As a result, it became impossible to activate PSM features via PSN Settings after February 29th, 2016, where the only way you would be able to run PlayStation Mobile software was if you had already activated PSM games from your console and still have the game downloaded.
On October 15th, 2017, developer frangarcj released NoPsmDrm, a program that could bypass the Copy Protection for PlayStation Mobile software by creating a fake license.rif file. For this to work, someone must have a working copy of the PlayStation Mobile software in question, and then use NoPsmDrm to generate a fake license to allow anyone to use that software on their PlayStation Vita,