Hello SpeedyPC,
Most important thing is that both applications provide the same level of protection.
SecureMe is free - no purchases or data limits and as a bonus, it’s able to scan Wi-Fi for security issues. But it has some limitations - it doesn't work on mobile data and it doesn't offer auto-reconnection feature, therefore the VPN will disconnect every time you change wifi. If you want to remove these limitations, you need to use SecureLine. In SecureLine you can also select location, via which you want to connect to the internet. These features are paid, otherwise the technology is the same in both applications and on the server side.
Hope it helps!