Whether you're out to find a way to limit data usage or just want complete control over your device's data connection (or both!), then DroidWall is the perfect app for you. With wireless carriers doing away with unlimited data plans and others throttling, more people have to worry about hitting data caps. If you're still one of the lucky few with unlimited data and are merely looking for more control, this app could still be the answer.
DroidWall is a front-end application that utilizes iptables to effectively block or allow data connection access for selected applications. This firewall is simple, user-friendly, and has many features that can be put to use in a number of ways. As a user, you can choose between two different modes:
White List - In which selected applications will be allowed data network access.
Black List - In which selected applications will be denied data network access.
In addition to the mode options, you can also select what connection type you want to block or allow, be it Wi-Fi or the one provided by your wireless carrier. So if you want to grant only Wi-Fi access to apps that consume large amounts of data, you can.
After the settings have been tweaked to your liking, you have the option to apply rules, which will save the settings and automatically restore them when you restart your device. Under "More," there are also options to enable logs, set a password for DroidWall, and, if you're a more advanced user, set custom scripts. If you know a thing or two about iptables, you can use those custom scripts to block access to certain ip addresses, set rules involving HTTP, HTTPS, SSH, and much more.
Android 4.0 Has This Covered
Now some of you may be thinking, "just wait a gosh-darn minute, features like this come stock with ICS!" - and you'd be absolutely right. ICS actually has an exceptionally clean data manager built right in, and it has quite a few more features, too. You'll be able to monitor which apps collect data, how much they're using, and instruct them not to do so. Not only that, but you'll also be able to set custom alerts that will send word when you're about to hit user-defined data boundaries.
While this is an incredible part of ICS, many of us may not even get a taste of what it has to offer unless we flash custom a ROM or buy new devices altogether. So for now, if you're going to be running an older version of Android, DroidWall is the best alternative. While it won't be able to alert you and it's more of a round-about type of circumvention, it is still very useful.
What's so wonderful about DroidWall is not only its simplicity, but usefulness. This firewall can be used to limit data usage and stay far, far away from those pesky data caps. Alternatively, you can cut off network access to untrustworthy apps and even remove ads (Editor's Note: We love and support the development community, so we strongly advise against blocking ads).
An app this useful has to be expensive, right? Wrong. It's free and you can check it out for yourself below.