Cameyo

The application is called Everything, and it can be found at www.voidtools.com.  It is an executable, but that's all I know as far as the type of installer.  Does that help a little?

Ah, that's funny: you actually did give the name of the application and I thought it was a generic name.

It turns out that it's an NSIS installer, so /S should work, but the problem is the way the script was written to create the installer, i.e. it not only installs silently but also launches the application.  The Online Packager can't complete the building process, because the application is open.

If you don't want to build it yourself, it seems there is a portable version on the voidtools website.

Not all applications are capable of being installed silently, so it is likely that you will occasionally run into some applications that can't be virtualized by Online Packager.  As for your list below, Rooler and Skype require network access, which make them ineligible for Online Packager.  If you extract tabbles.msi from the Tabbles installer, Online Packager should be able to virtualize tabbles.msi; I tested networx and Online Packager reported success.

Online Packager automatically finds the parameters for msi's (like tabble.msi) and it found the parameter for networx.

As for others, using Universal Silent Switch Finder is a great place to start.  If that doesn't help, an online search or a site like ITNinja or the specific software's site are useful ways of finding parameters.  I believe the way you entered the parameter for Everything was correct; it failed because of an idiosyncracy with the installer itself.  Be aware that some installers use "/" before the parameter and some use "-" so be watchful.  Good luck.