VPN for FSIS desktop and free AV!
I think standard F-Secure antivirus should be free, perhaps limiting some options such as Deepguard, etc. This would make you more visible in the market (many friends use avast, avg etc just because are free).
On the other hand F-Secure internet security it's ok to be paid, but should include VPN service. You already have the infrastructure from the mobile app freedome!