I've never been much of a one for MS Flightsim or any similar program - but then I've never gone more than 3 weeks between actual flights from the age of 17 to 31 (eek).
I found that as a flying instructor I had to deprogram several problems caused from excessive use or enthusiasm for MS Flightsim. Prior to a PPL course its use does turn people into IFR pilots who fly by never taking their eyes off the instruments. There are many issues.
The most useful program I ever came across was a free utility that taught me morse code in 3 days flat. The second most useful was RANT. It got me through my IMC and IR and I inflicted it upon all my instrument students and Integrated students. A couple of evenings playing about with RANT can save hours and hours in the air and for this reason I think it is exceptionally good value. Doubtless it has competitors now but way back last century it was fairly unique.
If you are looking for something useful to learn one wet weekend then try learning how to decode TAFs and METARs and Morse.
Cheers
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