Great news! 🔥 Now you have to tap on a booster or Rainbow blast just once to activate it! It used to require a double tap before, but now winning a level is even faster! 😱 At the same time, you can still activate boosters and Rainbow Blast by swiping it to the next cell.
Nonetheless, you can turn this off by going to the level settings and tapping the booster icon.

Please also note that if you tap on the Rainbow Blast it will remove the prevailing pieces on the field.