In order to use Ice Box correctly, the best thing is to have a rooted Android smartphone. Otherwise, you can still use it but you'll have to perform a fairly complex process for which you'll also have to connect your smartphone into your computer. That's why it's best to have a rooted smartphone to use the app.
Using Ice Box is as simple as picking the apps that you want to freeze and confirm the process. You can freeze as many apps as you want. If you ever want to use any of them, just unfreeze it and it'll start working like it normally would.
Ice Box is a really useful app that you can use to make sure that the apps installed in your smartphone (and you rarely use) don't waste your resources.
Android 5.0 or greater is required.