As you are aware, recently the LiberiOS 11 jailbreak tool was released for all iDevices running on firmware up to iOS 11.2.1. However, the main issue with this jailbreak tool was non-compatibility with Cydia.
Good news as FutureRestore has just been updated now to support Windows 7, Windows 8 and Windows 10. The new version 161 now opens path for iOS 10 and iOS 11 users (up to iOS 11.2.1) to downgrade their iDevices to previous versions.
After LiberiOS, Houdini has also came to the ground and released untethered jailbreak tool for all devices supporting iOS 11 up to iOS 11.2.1 including iPhone X, iPhone 8 Plus, 7 Plus, SE, 6S, iPad Air and Mini.
There is a dedicated YouTube app for iOS devices that is available in AppStore. It offers very nice interface and clean performance. However, the feature it lacks is ability to download videos on iPhone for offline viewing.