OpenHantek6022 is a DSO software for Hantek USB digital signal oscilloscopes 6022BE / BL. Development OS is Debian Linux, but the program also works on FreeBSD, MacOS, RaspberryPi and Windows. No support for non-Linux related issues unless a volunteer steps in!
The markers are for horizontal measurement only.
Press the right mouse button on the screen and move around to measure time/frequency and (if you're near a trace) voltage/amplitude at the cursor position.
I would like the spectrum processor to show the value of the peak of the spur. I don’t see how to view these values in your software release.