When you guess a word correctly you get a chest, which will be placed in the chest bar on the home screen. Tap on a chest in order to unlock it. Once you tap the “Unlock” button, a timer will start running. Once the time is up, you will be able to open the chest and get its prizes. You can use gems to open chests sooner. Bear in mind that you can only unlock one chest at a time.
By tapping on the chests you will be able to see the approximate number of coins and tool cards they contain. The longer the chest takes to unlock, the more prizes it holds.