LTA is testing wearables on 200 commuters for payment purposes. Each of them is issued a Sony SG50 smartband with NFC technology (to communicate with the payment system). They are partnering Singtel, Sony, EZ-Link, NETS and TransitLink for this trial which will last till 29th February next year.
Personally, I think this is a great idea. Hopefully, the Sony SG50 band can do more than just payment. If it is like any lifestyle bands that tracks walking distance and etc, it will be an added bonus.
Currently, topping up is only via the General Ticketing Mahine (GTM), Top-Up Machines and Add Value Machines at MRT, LRT and Bus Interchanges island-wide. In future, I believe you can top up via the Singtel mWallet app.