What is the Card Saver?
The Card Saver is a booster that unlocks at Level 110. It allows you to temporarily store a card from the playfield in a special slot, so you can play it later at a more strategic time.
How to Use the Card Saver
Tap the Card Saver Slot: First you'll receive a prompt asking if you'd like to spend coins to unlock Card Saver for three turns. You'll find the slot here:
2. Save a Card: Tap the card you’d like to save. It will move into the Card Saver slot for later use: 
The card will then move into the Card Saver slot:
3. Use the Saved Card: When you’re ready, tap the saved card to add it to your Letter Tray, leaving the Card Saver slot empty and ready to use again:
4. Swapping Cards: To replace the saved card, tap the Clear Letter Tray button. This will return the saved card and allow you to store a new one:
