My favorite way to explore the spectrum is using rtl_power to do very wideband multi-day surveys.
For general use SDR# is probably the best application for windows with secondary mono-based linux and Mac support.
The Sigma-Delta ADC samples at some high rate but low precision.
From this a 28.8 Msps stream at 8 bits is produced.
Because the devices use complex sampling (I/Q) the sample rate is equal to the bandwidth instead of just half of it.
For the data transfer mode USB 2 is required, 1.1 won't work.
I normally use Gqrx but it requires GNU Radio dependencies.