Data plans are where most people get in trouble with mobile phone bills if they have a smartphone and a data plan that has limited bandwidth each month. You start streaming movies and watch one or two and depending on your plan, you could be out of data for the month and end up with a giant bill.
A new app for Android users called My Data Manager has turned up that will track your data usage and will give you a breakdown of how much data you are using and where you are using it. The app will also aggregate all of your data use so you can keep up with you total monthly allotment.
The app also has the ability to trend your data use for the last 30 days. Ideally, you will check the app and notice that you are running out of data and stop streaming before you end up with a $500 bill with data overages. The app will work on Android 2.2-2.3.3 devices.