Attack on Titan: Roar of Awakening is the third compilation movie, that compiles episodes 26-37 of the TV anime; i.e., from the end of the compilation compilation movie until the point where the second season of the anime ended. It was released on January 13, 2018 in theaters across Japan.
Overview: In the third compilation movie, episodes 26-37 of the anime are retold, compiling the second season of the anime. The movie retells one story arc: the Clash of the Titans arc.
Summary: For just over a hundred years, humanity lived in peaceful ignorance within the Walls safe from the threat of the Titans until the day the Colossal and Armored Titans came to Shiganshina District, breaching Wall Maria and reminding humanity of the hell beyond the Walls. Five years later, humanity discovers that some of their Titan foes are hiding among them as humans, and in Stohess District they capture the first of these Titan spies: Annie Leonhart. As Annie's crystal is restrained and carted away by the Scout Regiment, several soldiers look up the ruined section of Wall Sina where the Female Titan attempted to scale the Walls.
Source: Attack on Titan: Roar of Awakening, available under CC BY-SA 3.0.