Boosters come in different types: those you activate before doing a level (pre-boosters) and those you can activate during levels. 

Pre-boosters:
  • Super Boots: Oliver's movement speed increases significantly.
  • Rainbow: Any room you place the guest in will count as the room of the color the guest wanted.
  • Tycoon: The first guest will be a VIP who pays triple for your services. This can be helpful if you're struggling to earn enough coins to complete the level.
 
Boosters during levels:
  • Magic Wand: Instantly fulfils all current guest orders and cleans all currently dirty rooms.
  • Candy: Resets all guests' patience back to the start of green.
  • Shuttle Bus: Transports any departing guests currently waiting for a taxi.
  • Switcheroo: Use this booster when a guest wants to check into a room that's unavailable (either because it's already occupied or hasn't been cleaned). The first and second guests in line will swap places and regain their patience. This gives you time to clean a dirty room or wait for one to free up.