The last that was reported concerns CloseWhatsApp for Symbian devices passing the 1.3 version , from the previous numbered 1.2. We do not know what are the changes made, it is likely that this is just an update that should resolve some bugs.
For those not familiar, the app allows you to terminate any process CloseWhatsApp active application WhtasApp to avoid that always remains connected even when not needed. Do not have an interface, everything is handled through the special button that will add to the homescreen that will act as a switch onoff.
Compatibility is guaranteed on all Nokia Belle device, follow the link.