The app (and the accompanying widget) gives a quick overviewoftalktime remaining as against days remaining in the currentbillingcycle. In the app, you can even go back to the previousmonth (justto check how honest your telco has been perhaps!)
Remember this app gets call duration from the phone. Thecallduration shown is indicative as your telco may deriveitdifferently.
Cheapskate (like me) on a postpaid plan? It's free and youneedit!