In Find Mode, you need to use the letters that the game provides to form certain words that are required to complete the level. To get clues and complete your board, you can use different Boosters and the Bonus Bar.
You can spell words that aren't required to complete the level, and that will fill up a Bonus Bar. Once the Bar is complete, a letter tile will be revealed. The longer the words are, the fastest the bar will be filled up so you can get the Bonus. Also, if you tap on the Bar, you will be able to see the words you've already found.
Random Letter Clue: it reveals one of the hidden letters of the words you need to complete the level.
Pick Letter Clue: It allows you to pick the letter you want to be revealed.