VOAProp

The late Julian Moss G4ILO wrote a great piece of software (indeed he was a very prolific software writer) called VOAProp. This makes use of  VOACAP "the result of more than 50 years of R&D into HF propagation" and displays it in simple graphical form in a window that you can keep running all the time.
It automatically downloads forecasts from VOACAP and you can select whichever amateur band you are currently operating on and see the predictions for the current day. I have found it invaluable and have made a lot more 30m contacts in one day than the previous year since installing the software.

Here the 40m band is shown with predictions for likely signal strengths
based upon the current time, my QTH and VOACAP predictions.

Here the 30m band is shown for the same time of day as above

Right click is your friend on this program.
There are quite a few options that you can set on this menu

You can also left click on the screen to select a pick point where to place
a DX station. Obviously this can't be very accurate but you can improve the
resolution by right clicking to produce the side menu and then enter the
grid location in the box.

This is very useful when using digimodes for example where the sender
normally transmits their grid location.

In this example I have selected a location in Hungary and the S meter in the bottom
right hand corner displays its predicted signal strength. This is based upon the High/Medium/Low slider which
models the power of both transmitters through a dipole or beam. The slider has 10 positions so can approximate your particular radio/antenna combination. The results show different contours on the map.

All in all I have found this small software package really easy to use and a great graphical front end for the VOACAP software.

You can still download VOAProp from Julians website g4ilo.com

and VOACAP from voacap.com