Please take note, TnG recently has an app update (iOS) and they have intentionally changed the interface and hid the 1% fee to “encourage” users to top up using their Singapore issued cards.
Picture on the left is what you see, you need to click on the tiny word breakdown before you’ll be shown the fees. Previously everything was on one page without the need to click on breakdown. TnG management very smart, going forward, they can charge 10% fee covertly and unaware TnG users will only find out after the top up is done.