A: Install the "Tuber" app from the App Store (if you can find the legacy version) or simply use the Chrome browser (last compatible version: 48.0).
Since the old apps are broken, using the web browser is currently the most stable way to watch YouTube on an iPhone 4. youtube for iphone 4 ios 712 download upd
Click or Download so the app is added to your account's purchase history. A: Install the "Tuber" app from the App
The YouTube app is compatible with iPhone 4, but it requires iOS 6.0 or later. Since your device is running iOS 7.1.2, you should be able to use the app. youtube for iphone 4 ios 712 download upd