This app calculates Expected Bill of Sui Gas (SNGPL, SSGCL) according to latest HM3 rates/OGRA tariff. It takes care of complete and latest tariff by OGRA and OGDCL. It asks the user for Previous Reading which can be seen from last months bill. Latest Reading which you can get from the Gas meter. GCV which is mentioned on your previous bill and usually around 900 to 1200. It also warns you if your bill going close to high HM3 rate.