Question marked as Best reply User profile for user: Rigo_O86 Rigo_O86 User level: Community Specialist Nov 30, 2016 12:06 PM in response to Xxxxxxxxxxxxxc Hi Xxxxxxxxxxxxxc, I understand you'd like to download an app from the app store. This article has some information on how to Install an app on an earlier version of iOS or OS X . The listing on the App Store for the YouTube app is below. YouTube - Watch and Share Videos, Music & Clips on the App Store The information on the page indicates that iOS 8.0 or higher is required, so your iPhone 4 isn't compatible with the modern YouTube App. If you are unable to install the app, it is for this reason. Hope that helps. Thanks for using Apple Support Communities. Show more Less Reply Link