You can download the FPL desktop app if you log in online, click the 'settings' button, then the 'downloads' tab.
https://www.freephoneline.ca/downloadDesktopApplication
The app does download, I just tested it. Maybe try another browser and see if that makes a difference.
I only use the IOS version of the Fongo app so I can't comment on that, but I can't believe it just doesn't work, Fongo would not have released it if it didn't
Remember Fongo and FPl accounts are separate, so you can't log into each others systems; only the system you signed up on. This is why a lot of people end up with multiple accounts.