The other day I showed how you can use an Android Tablet to wirelessly connect, control, and display a Live View video feed from a Panasonic GH4. If you didn't catch that video, it's a very cool feature to have when shooting with the GH4 (found here).
Wireless Control and Live View for Panasonic GH4
If you're shopping for a tablet with an excellent display, plenty of horsepower, and most importantly connects to the Play Store to download the proper Panasonic Image App, there's a deal on the Samsung Galaxy Tab 3 7" version (refurbished) for just $119 (found here).
Samsung Galaxy Tab 3 7" Android
I find the 7" size is manageable without being oversized. If you're looking for a simple way to attach a tablet over your camera, i've been using this universal Square JellyFish clamp. Folds up small, very good build quality, and perfect for tablets 7" or under . It offers a tripod mount, and can be used Horizontally or Vertically (found here).
7" Android iOS Tablet Spring Clamp with Tripod Mount