With off chain transactions, what's the point of using a cryptocurrency then? I always believed that off-chain transactions far better suit centralized applications, as using it with a cryptocurrency basically makes the cryptocurrency itself irrelevant in the scheme of things since the transactions are done off-chain.
The whole point of OtherCoin is that it transacts _Bitcoin_, so there's no centralized authority that guarantees the funds. Whenever you want to get out, you don't have to check if the central issuer is still in business and they can't block your request or ask any questions - OtherCoin simply secures the transfer of _Bitcoin_ private keys that can be instantly redeemed on the blockchain. So it's off-chain but decentralized. The cryptocurrency is not irrelevant - it's the way you get your money in/out of the OtherCoin system. In most (all?) other off-chain systems, the central authority can not only track your payments (you tell them when you want to pay someone) but also control your deposits and withdrawals. With OtherCoin, deposits are simply Bitcoin payments to a random address that the app generates, withdrawals are simply private key sweeps (the app tells you the private key and destroys it from its secure storage). Transactions are off-chain and anonymous (you move Bitcoin private keys between offline devices).