This app doesn't actually find icon files for you. You have to navigate to the Resources folder of an application to find the .icns file. If you really need a catalog of your application icons, this app can help you build one. But it's a lot of work and, at the moment, there's nothing you can do with the icons once you've collected them.
On the other hand, if you copy and paste an icon from the Get Info window into Preview, you can view - and use - any of the icon images in the file. If and when InerziaIcon can duplicate this function it may be more useful. Until then it's a one trick pony. Of course, there are any number of apps out there that enable you to create and/or edit icons so just how much of this functionality will make it into InerziaIcon remains to be seen. What might be more useful is for the catalog capabilities of InerziaIcon to be integrated into one or another of these other applications.