Here is a sample of how a VPN can effect Internet speed when used with Android devices. Remember that many factors will influence your speed, for better or worse; this is only an example, and the speed will vary from user to user.
Also, please keep in mind that when you’re connected to Hotspot Shield or any VPN service, data going in and out of your device travels through the VPN servers first before reaching their target. That's how internet anonymity is achieved and why it's normal to experience a speed reduction of 30%–50% when using any VPN service.
With Hotspot Shield Premium on Android:
With Hotspot Shield Free on Android:
If you have a free account, you can try a Premium account for free here.