for readability Underway I prefer Skymap (
www.sky-map.de). Also nobody shows the weather radar image better then they do
I have flightplan, also the online version, skydemon, rocketroute, eurofpl & navplan pro.
vfr I usually use skydemon or skymap, ifr it is a mix.
First is eurofpl .. it is the easiest and fastest
the other day I planned edny-ehrd and did not like what I saw from eurofpl, thus I looked at jeppesen & rocketroute. Ultimately it was Navplan pro which found the shortest route.
flitestar and internetflight planner have a nice weather feauture were you will find a rough estimate of the cloudbase and cloudtops enroute. This feature I like!