Well, seems like Twitter Counter is effective for you. You need even more advance statistics as your account grows and you've got more followers than your account can handle. 

Please follow these steps to upgrade:

  • Log in with your account and go to "Settings".
  • Select "Subscriptions".
  • Then click the grey "Show details" button.
  • Click "Upgrade/Downgrade.
  • Choose the plan you want and hit "Upgrade Now".
  • You will be charged for the difference between the "old and "new" plan right away.