Every day that you complete all your health tasks, you will earn a Heart. A heart will allow you to add a gift card to your reward pool (this is the pool of gift cards you could win when you play a game in the app). π Note: You can only add a gift card to your reward pool if it is available to your level. Levels are like having access to new doors and hearts are the keys to unlock them.
By going to Rewards then My Rewards, you can customise your reward pool so that you only win rewards from your favourite places e.g. Netflix or Amazon (provided you have unlocked them).
When you unlock a reward with your hearts, you are not winning it, so you can't claim it (yet!). Unlocking a reward gives you the chance to win it every time you play a game in the app. If you leave a reward locked, you will never be able to win it.
Unlocked rewards can be won multiple times, and will remain unlocked until you lock them again. Learn more about winning rewards here.