We use Futrli for forecasting, although I'm planning at some point to trial Castaway and potentially change.
However, we've been asked a couple of times recently to do a business plan, rather than just forecasts. There's a few websites that (apparently) pretty much write it for you (LivePlan, Enloop) but the forecasting element seems a little basic though (admittedly I've not trialled anything yet, just looked at their websites) and had thought of signing the client up for it, then once it's finalised cancelling the subscription,. All seems a bit of a faff, but I can't seem to find a software aimed at accountants/advisers/consultants etc.
What do people use for full business plans?