I maintain that the KiwiSDR has been one of most value for money and interesting pieces of amateur radio equipment I have purchased.
One of the main reasons for that view is the continual updating of the software and the addition of new features. The latest is Radiolocation using Time Difference of Arrival (TDoA).
A review which provides the detail is here:
A test was performed against DDK, a RTTY weather service originating from near Hamburg in Northern Germany. Frequency 10100.8 KHz.
Three KiwiSDR were chosen, based on good geometry to the known location of the target – G0LUJ, F1JEK and UR5VIB. The test was successful.