The following steps can be tried to resolve issues with the ColorTRUE app hanging, or getting stuck during the profiling process:
Make sure the device being profiled has a full charge. With iOS devices it is possible to attach the sync cable while profiling, this has solved power issues in some cases.
Make sure there are no system messages appearing on the screen. For example: "You have just 30% power remaining". These system messages can force them to the top causing the profiling process to be interrupted or cause an error.
Make sure the measurement hardware is sitting flush to the surface of the phone or tablet being profiled.
Make sure the measurement hardware is placed on the phone or tablet in such a way that it is measuring only color swatches being displayed. In other words make certain that the measurement hardware is not including part of a phone bezel in the measurements.
Make certain that the screen of the phone or tablet is perfectly clean and does not contain any fingerprints
Make certain that the screen is not dimming during the profiling process.