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I prefer a widget called Application Update. It takes a little setting up but I find it is more manageable than AppFresh.
 
If AppFresh changed any system files, you would need to enter your administrator password. Since it's a simple drag and drop to install you know that it's not changing anything important. I've been using this on two computers for nearly a year and love it. Definitely worth a download.
 
If AppFresh changed any system files, you would need to enter your administrator password. Since it's a simple drag and drop to install you know that it's not changing anything important. I've been using this on two computers for nearly a year and love it. Definitely worth a download.

I tried tis one today and it gave me a list of programs it needed to update, but they were the latest versions. So most were false positives.
 
I've used AppFresh for quite some time and it works great! As you can see from this link, it's also beating out Firefox as one of 'Top' apps out there for Mac users (at least among application junkies)...

Another alternative that you might want to consider is VersionTracker Pro (though this app is not free)
 
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