EvaSmartCylinder app for iPhone and iPad

EvaSmartCylinder is a cylinder that uses ultrasound technology to measure how much gas left inside and connects to your smartphone via bluetooth.
To pair your smartphone with EvaSmart, press and hold the button on device. Blinking lights means that your device is in pairing mode. Then add the device on app main screen. (*You can add multiple EvaSmart cylinders to the app.)
Now, you can check your current gas level in app. EvaSmart also periodically measures the gas level and sends all stored results to the app. With this stored data, the app generates a graph showing the consumption history and estimate the remaining time to run out of gas. You can also set an alarm threshold to be alerted when the gas level drops below the critical level.