Data saving mode : To reduce your data bytes sent/received
Privacy protection mode : To change your original IP address
Its used to change your IP address to some random one of some other country or server instead of your local server. This is usually used to protect your privacy when you want to hide it from prying eyes. Websites you visit will not know your real IP address instead what they will get is a **bleep** IP belonging to some other server. Besides this the app is also used to reduce your internet usgae so that always some less data bytes are sent and receievd but this can reduce the quality of some pictures, videos as you will be using less data to load them everytime. This is basically needed to be enabled if you are on a limited Internet plan.
But overall this app can slow down your Internet connection sometimes its fast sometimes its very slow.
