TapCheck: Transit Card Balance

Hold a Korean transit card to the back of your phone and its balance and recent
trips appear. TapCheck reads over NFC what is already written on the card, and
does nothing else.


HOW IT WORKS

1. Press the big button on the home screen.
2. Hold your transit card to the back of your phone.
3. The balance and recent trips appear.

It usually takes about three seconds. There is no sign up and no account.


WHAT YOU SEE

· Balance: what is left on the card
· Trips: the last 20 entries the card recorded (boarding, alighting, top up, refund)
· Wallet: keep up to five cards you use often, told apart by colour
· History: every check is kept on your phone and drawn as a balance chart


READ ONLY

TapCheck cannot top up, pay or refund. It only reads what the card already
holds. Nothing is written to the card, so checking a balance never changes it.


YOUR CARD DATA STAYS ON YOUR PHONE

· The balance and trips it reads are stored on this device only. They are never
sent to a server.
· The card number itself is not stored. Only a hash used to recognise the same
card again, and the last four digits, are kept.
· There is no account to create. You are never asked for a name or a phone number.
· The network is used only to fetch ads. The ad provider collects device
identifiers such as an advertising ID in order to serve them.


WHAT YOU NEED

· An Android 10 or newer phone with NFC
· A Korea wide compatible transit card (KS X 6924)
· T money, Cashbee, Rail plus, Onepass and Hanpay cards are recognised

The NFC antenna sits in a different place on every phone. If a card will not
read, move it around slowly, and take off a thick case.


GOOD TO KNOW

· An ad is shown at the bottom of the screen.
· TapCheck can remind you once a day to check your balance. You can change the
time or turn the reminder off.
· This app is independent and is not affiliated with any card issuer or transit
operator.
· Some journeys may be missing if the card did not record them, and what is
available differs by card type.
· A postpaid card carries no balance on the card itself, so no balance can be read.