A "true sequel", which takes place in the Beta Timeline, where Okabe had given up on saving Kurisu. He returned to his daily life, but was suffered by the flashbacks of the other timelines and the death of Kurisu.
There's a system known as "Amadeus" existed, which is still in the stage of development. It was able to save human's memories. Okabe was told that the Amadeus was inputted with Kurisu's memories and he was requested by Alexis Leskinen, a professor to cooperate with him as a Amadeus tester. The Amadeus was inputted with Kurisu's memories before she had ever met Okabe.
It will include stories from three of the Steins;Gate novels, as well from some drama CDs. (taken from VNDB)
Title ID: BLJM61303 Firmware: 4.76 (OFW update included, beware)