More than 1000 downloads and just 35 estimates?! Do not be lazy, rate the application, it's totally FREE!
https://play.google.com/store/apps/details?id=org.karbo.karbon#details-reviews
https://play.google.com/store/apps/details?id=org.karbo.karbon#details-reviews
Sorry i have ios but next time i will vote on phone my father