Use Google's mobile YouTube site instead of the iOS YouTube app
How to stop iOS from launching the YouTube app
Here's how you can stop iOS from launching its native YouTube app. This will let you use Google's mobile YouTube site instead.
1. On your iOS device, go to Settings.
2. Go to General.
3. Go to Restrictions.
4. Toggle the On switch to Off for YouTube.
5. This will stop iOS from automatically launching the native YouTube app on your iPad, iPhone or iPod.
For more, see the original article at the link below.