Short answers, pulled from the story.
Final Fantasy XV: Pocket Edition is a 2018 action role-playing game co-developed by XPEC Entertainment, SummerTimeStudio and publisher Square Enix. It is an abridged version of the 2016 title Final Fantasy XV, remaking the storyline, graphics and gameplay for mobile devices.
Final Fantasy XV: Pocket Edition released for Android and iOS on the 8th of February 2018. A Windows 10 version followed on the 6th of June. Console versions, titled Final Fantasy XV: Pocket Edition HD, arrived on the 7th of September for PlayStation 4 and Xbox One, with a Nintendo Switch port on the 13th of September.
Hajime Tabata, director of the original Final Fantasy XV, co-produced Pocket Edition alongside producer Kosei Ito. Ito had previously worked with Tabata on Before Crisis: Final Fantasy VII.
Final Fantasy XV: Pocket Edition is split into ten chapters. The first chapter is free, while the remaining nine can be purchased individually or together at a discount.
Final Fantasy XV: Pocket Edition received generally favorable reviews, according to Metacritic. Mike Fahey of Kotaku called it an outstanding abridgment, Shaun Musgrave of TouchArcade gave it five out of five stars, and Megan Farokhmanesh of The Verge praised its streamlined gameplay and redesigned art style.
Final Fantasy XV: Pocket Edition was built using the third-party Unity engine, unlike the original Final Fantasy XV, which used Square Enix's in-house Luminous Engine.