In January last year, Ubisoft confirmed that their subscription service Ubisoft+ was going to be released for Xbox after previously only being available for PC. Since then, we haven't heard anymore about this, but it seems like we won't have to wait much longer.
Last month, many people noticed that some Xbox titles on the Microsoft Store suddenly had a Ubisoft+ tag, probably a result of someone being a little to eager to press the publish-button. Now TrueAchievements has scanned the database for the store and found 63 Xbox games (click the link to see all titles) confirmed for Ubisoft+ and over 100 DLC items. It pretty much includes all the best from Ubisoft.
Unlike EA Play, it does not seem like Ubisoft+ will be a part of Game Pass, at least not included with the current monthly fee. For PC, the subscription costs €14.99 / £12.99 per month and we assume it will be roughly the same for Xbox.