You can get all the available PowerUps using the coins you obtain by winning games and participating in game modes such as "Guess the Word" and "Word Search".
To obtain them, you must enter the Shop, which you will find in the lower left corner of your screen. When accessing it, you will see your coin balance in the upper right corner.
When you slide down on your screen, you will see the different packs that you can purchase from each one of them, with their respective price in combos of 1, 3, or 5 power-ups.
Now you can also buy PowerUps during games! To display the Shop, you must press the PowerUp you want to buy, which you will see above the game board.
Once you do, you will see the different options to compare PowerUps, and you can use them in the game you are playing.