DroidWall

Whether you want to cut down on data usage or seek total control over your device's data connection, DroidWall is the ideal app for you. The app acts very much like a desktop firewall and allows you to choose which other apps can access the internet, and which ones cannot, leading to increased protection of your device and less worrying about hitting data caps, especially for those who do not have access to Wi-Fi 24/7.

DroidWall has a very simple dashboard control letting you decide which apps access the internet and how. Each app is listed with two checkboxes: one is for Wi-Fi data access and the other is for cellular data. It means you can grant only Wi-Fi access to apps that use large amounts of data and cut down on your bills by reducing background data consumption. Check the box to allow access or leave it blank to deny access to any particular app. Activate the firewall when you are done.

Do keep in mind that some apps solely depend on internet access. So if you mistakenly block your browsers' internet access on Wi-Fi and 3G, you won't be able to surf. Also, you do not have to worry further about app advertisers tracking your location or apps uploading personal data. Remember though, your device must be rooted before you can use the app.