Just found code for 10% off ANY Skybus ticket.
Works at all locations and can be used online or in the App.
Tickets valid for 3 months from date of purchase
See website for full terms and conditions.
Not sure of expiry of code
Also, if you are traveling as family.
Cheaper to buy on return tickets:
1 adult and 1 adult + children separately
2 adult + children option
(at certain locations)