Grade123 come with a learning video library for 1st/2nd/3rd grade kids that include 24 learning topics and thousands learning videos. GoKindergarten provide a convenient way to view, discover, organize and aggregate learning videos from YouTube. There're enormous number of kids learning videos, playlists and channels available on Youtube, You can search and add learning videos in the app quickly, your kids can watch it anytime later.

* Watch kids learning videos on iPad.
* Include 24 learning topics.
* Include 100 most subscribed learning channels.
* Easy to manage the video library by yourselves.
* Enhanced video player that support continuous/repeat playing and HD quality.
* Easy search(videos, playlist, channel)
* Intuitive UI that designed for Kids.
* Parental control for video access.
* Video navigator for parent.

Usage: Tap "+" to add, long press (tap and hold) to delete.

Note:
Enable parent control on setting panel to control video access and setup the passcode for video navigator if you don't want your kids to be exposed everything from YouTube.

Please try following procedure if you have no sound issue.
1. Flip switch volume button on the side of iPad
2. Go Settings -> General -> Use Slide Switch to: -> Mute, then turn on the switch button
3. Double tap home button -> Swipe to the right on task bar -> Tap the speak icon off/on
4. Restart app.

See more detail here : https://discussions.apple.com/thread/4984822?start=0&tstart=0

Disclaimer:

All video images and videos are from YouTube and is available in public domain or published under authorization of their respective owners. This app does not upload/store any videos/clip. This app just provide a convenient way to organization, discover and view videos from YouTube.