$8 Sign-up Bonus via RebateMango + 10% Cashback Bonus for 1-Year + 20% Cashback Promo Codes in May for UOB Cardholders
I signed up through the URL and got the $8 sign-up bonus straight away, didn't really check if I was a UOB card holder.
Not super clear on how the 10% bonus cashback works from the T&Cs, but it sounds like you get an extra 10% of the cashback (e.g. if Expedia is 6%, you will get 6.6% for 1-year) provided you purchase through https://rebatemango.sg/mighty. Does not mention you have to use your UOB card to purchase.
20% promo codes available for AliExpress, Cotton On, iHerb, and Charles & Keith via UOB app (but limited redemptions).