I use Flightstar/IFR from Jeppesen. Ordinarily, I would never have bought it because of the cost, but it came bundled in a deal with JeppView and GPS NavData.
As a tool for IFR planning it is not bad at all, with polished maps and routing options. It does betray its US roots in a number of respects though, which can make it a bit irritating to start with, until you have configured it to meet your own needs. Generally though, perhaps 9/10 with only the price going against it.