i love how fast the 29W USB C charger charges my iPad Pro 12.9 inch. I want to get the same performance at work without having to pay $70 more for the convenience of having two chargers. I bought a third party USB C 29W charger and a USB-c to lightning wire. Is there an app in the App Store that can compare if these third party accessories are charging my iPad as fast as Apple's official USB C charger? Or am I just going to have to compare them the old fashion way and time how long it takes to charge the iPad from a drained battery?