When image search won't work, or the app has trouble saving / freezes in a classroom, it's usually because the internet connection in use is blocking certain types of activity by a firewall. Most commonly, we see this from people using Haiku Deck in school districts, computer labs, and other public places.
The culprit here is most commonly Flickr being blacklisted on the school network. Flickr.com is the domain our image search works through and pulls images from.
If you find that your network is indeed having trouble because of a network firewall, most users have had success approaching the IT department in charge of the network and requesting to whitelist flickr.
If not, I recommend trying the following:
1. Check and see which network you're connected to. You can check this on the iPad by going to your Settings (the app with the silver gears icon) and looking under Wi-Fi to make sure the network with the checkmark next to it is the right network. On a Mac, you can click the wifi symbol in the top right corner of your screen, and on a PC, you can usually find the wifi symbol in the bottom right.
2. Try another network if a reliable one is available. Usually, a good network to try is a home network, since home networks typically do not have content or site filters on them.