Standalone Flash player app for swf -files I use nowadays Opera because it just works for these swf -files. 
No other browser work. 

However, the problem with Opera is that it is big. 

Is there any tool by which you can just view SWF -files?
Did you already visit Adobe?

Adobe provides a standalone Flash Player: Flash Player Projector 16.0.
Additional also debugger versions are available as well as older versions. 

Originally it was meant for Flex and Flash developers. 

Example: Starting a flash game