To answer the first question:
Sadly, Fogger is Dead and it died around the time of Ubuntu 12.10. "loneowais", abandoned the project pretty much immediately after the Ubuntu App Showdown was over.
Source: I was a part of the FogApp Authors and wrote multiple FogApps in the project.
webbrowser-app is a great suggestion and I'd also like to point out that it supports the "--fullscreen" option to start in not just maximized but completely fullscreen, which is cool for some scenarios.
webbrowser-app also "--app-id=" which is a controller for Sessions, it allows you to give a unique identifier to create a persistent session for the identifier and if you reuse that identifier again it will return with that session. This feature allows you to have multiple instances of the same webapp logged in with multiple different accounts. This would be really cool for say someone who has many different Gmail accounts.
There are some more options to create Web-App Desktop Applications as well.
Epiphany, aka GNOME's Web, has support for Web-App Desktop Applications including multiple sessions.
Midori has support for Web-App Desktop Applications including multiple sessions.