Just read abit about how it works. It doesn't really reverse people transactions(all Bitcoin transactions) on Blockchain like some made it to sound. Their system just help coin senders reverse only their transaction when receivers type codes/password meant for them wrongly(probably typing the codes wrongly multiple times will cause the reversal).
Well, it's an interesting solution to irreversible transaction "problem" in Crypto... only that it relies on third-party & centralization to achieve this.

I guess the fees for complete transaction will increase abit for the sender. And I wonder if the sender will always have to send the codes to the real recipient before transaction is possible... that will probably be better for significant/large transactions.     The receivers always needing to get the codes first before receiving funds could complicate things abit for them unless the process is fully automated and quick