A simple heat input and gas rate calculator for timing Natural Gas installations. Time the Metric meter for two minutes, input the first and second reading, press calculate and your answer is there.
For imperial meters time one revolution then convert the time into seconds. input that time, press calculate and your answer is there.
No more looking up charts or using long winded calculations... Its so simple

What’s New

Version 3

minor glitch fixes for IOS 10

Ratings and Reviews

3.8 out of 5
10 Ratings

10 Ratings

micmac1962 ,

Nice app

Have used the free version on iPhone.
Reason for changing to the paid version is that the stopwatch responds immediately compared to the free one and appears to lag.

Hit factory ,

Good app liked older version better

Have used this app since I first got an iPhone 4 works really well unless meter is in the .900 then meter resets to zero it wont calculate it but not a prob at all. The new updated version for ISO 10 is no longer full screen old version was much nicer not sure if this can be sorted but will continue to use it as I love the app.

nickcam ,

Getting certified

This a great app , but have found out through my company its not been certified by gas safe and should not be used , please could you do this, so i and other can trust the result given , as this is a great tool for gas rating , then more engineers would use this app.


George A Brown
14.4 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad and iPod touch.



Age Rating
Rated 4+


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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