AppleUKNW:
I was anxious to try your download for the script since, although the Unix command works, it still is not a fix. My Skype (yes, I know it is not an Apple product) still gets stuck and won't activate the camera after the next time I use it, which could be a day or a week later.
I launched the script, but was unclear what to do.

At first, the name "Disable" seems odd, but I guess that is what it needs to do - disable iSight which is still being held captive by an app. I am running El Cap, so that seems to be compatible, but I wasn't sure which button to choose, Enable, or Disable. I launched the script and chose Disable, and launched PhotoBooth. No Camera Connected. That is is ok - I would expect it would have to Disable before it could enable. I quit PhotoBooth and launched the script again, this time I launched the script 2 times - the 1st selecting Disable, and the 2nd selecting Enable, since that made sense to me. I launched PhotoBooth again, but still No Camera Connected. I tried varying combinations, but nothing worked. One combination was to launch the script, click Enable iSight, then launch it again and click Enable iSight again. However that brought up the following message:

If I select Edit, it simply opens up Script Editor, and I have no idea what to do in there. 😉
So I am still stuck with the one-time Unix command, which saves me from restarting my computer. There are still several others I know that would not want nor know how to use the Unix command, so I tell them to restart the computer.
I was really hoping this would be my cure. If your or someone can tell me what I'm doing wrong, it would be nice to know.
Thanks!