As mentioned above, all of them are paid, but if you don't want to spend real money, you can use Shell Shockers codes that developers share from time to time. Those looking for the latest Whispers ...

no more one day old accounts being able to chat. this was a mistake. i decided to open-source this to prove that this only impacts the players who are not fortunate enough to be able to play Shell ...

PigeonProxy lets you play Shell Shockers under any filtering service that uses the PAN-DB filtering and categorisation IP/URL database from Palo Alto Networks (which means, at school!) Blue Wizard ...