Good for payg Widget shows cost and other usage. Setting it up is a pain. There are preconfigured settings that you can import. This is good with Dodo $2 payg or yomojo payg. You can set up widget to show either remaining balance or how much you have used. Plans have to paired with rules. If there are special numbers  rules have to be paired with numbers. Best app for payg  doesn't have anything to exclude first 200mb or first 100 minutes.
March 12 2016