You will find the PowerUps in each game, on the upper part of the screen, in the bar on the game's grid.
You will see the PowerUps with their corresponding icon and the number you have of each one.
By taping on the '?' icon, you will be able to see information on each of the PowerUps:
Top Play: shows the best word you could have played once the turn is over. Bear in mind you need to select this PowerUp before your turn ends.
X-Ray Glasses: shows all the cells in which you can place your tiles.
Word Spotter: shows the position of the top scoring word that the user can play.
Magic Play: plays a word automatically.