Know your limits. Apps like My Data Manager track your data usage and set off an alarm when you're close to your monthly max so you don't incur additional charges.
A data-packed app that’ll keep you fully informed of all your data-gobbling habits. It’s especially useful for people on limited data plans who want to avoid overage charges, but is still handy for people with unlimited plans who want to avoid throttling.
The alarm function is very usefully and can actually save you money.
My Data Manager is an extremely robust application that gives you a handful of ways to track your data usage… My Data Manager is hard to beat.
The first step involves getting a handle on how much data you automatically consume. Most people don’t know. Try using My Data Manager.
New York Times
My Data Manager has nice features, such as one for setting an alarm to let you know when you’ve reached your daily budget. It also lets you track data use on shared or family plans so you can tell who’s been using the most data.
The Wall Street Journal
Use Wi-Fi wherever possible and get My Data Manager to track your data usage.