I believe most of the smartphone users has made smart phone monthly subscription plan with some tele companies, so do I. Most of the subscription plan includes 3G/4G/LTE data plan, voice call minutes, SMS, MMS and maybe voice mail. If you are heavy voice call users, you make a lot of call everyday and you worry you use exceeding voice call monthly minutes quota, then you may need an apps to monitor the total voice call in minutes you have made in a period of time. To me, I use SMS mostly and I do monitor how many total SMSes I have sent out to avoid extra changes once it hits the quota. I would say, exceeding SMSes and voice call quota is not a big deal as it doesn’t charge that expensive. How about exceeding your 3G/4G data usage limit?? It is headache when you see the bill at the end of the month.