Nx Viewer Panasonic Exclusive |link| 〈ORIGINAL – 2027〉

If you are referring to Panasonic computing hardware, "viewer" usually refers to pre-installed system utilities such as:

Preloaded on Panasonic NX-series devices (FZ-N1, FZ-T1, etc.).
Distributed via Panasonic’s enterprise software portal or custom ROM images.
Tied to the device’s specific kernel drivers for hardware acceleration of touch/scanning input.