AccuMark allows you to capture location events from your iOS device and average them over time. GPS location fixes are subject to various error factors. However, over a period of several hours, measurement errors have a tendency to cancel each other out. Depending on the measurement duration, local GPS reception conditions and solar activity, the achieved final accuracy can be less than one meter/yard. Please note that there is no guarantee on the final accuracy.

The concept of AccuMark implies use of the GPS hardware of your iOS device over a long period of time. Therefore you should use AccuMark only while the device is plugged into a power supply, for example an external battery pack. If you do not do this, AccuMark can drain the battery of your device fairly quickly.

To use AccuMark, position the iOS device at the location for which you would like to determine the coordinates. Then press the location button. The button will highlight to indicate that the application is taking samples. AccuMark plots all samples in the plot area. AccuMark will only consider samples that fall into a circle with a diameter of 20 meters for averaging. If you press the + button, AccuMark will toggle between showing data for all considered samples and showing data that lies within 1.8 Standard Deviations of the current mean.