Your one stop shop for your Flowback needs. Calulations-Strap Calc-Bean Choke Calc-Multi Choke Coefficient Calc-Nitrogen to Gas Calc. Hydrometer Chart. Timer. Terminology. Chat Forum. Flashlight. SDS Online. Oilfield RSS News FeedThis app is ad free. This app also uses Internet for SDS, Forum, Rss Feed, and Terminology so data rates may apply. This app also uses camera function in order to use the flash on your phone for the flashlight, but it does not access your photos.