This is another great initiative. I really love that developers do this for the organizations we should all be supporting.
Although FlightGear is not exactly a sim where you see a lot of product sales going on (or at all?), FGUK decided to do something different.
The team released a livery for the (freeware) EC-135 but they are asking you to contribute with some money. Not to them, though, but to the actual organization this livery replicates the livery of.
If you download the EC-135 Scottish Charity Air Ambulance livery, FGUK asks you to make a donation to the Scotland’s Charity’s Air Ambulance and, by doing so, you will be helping quite an organization that is saving people daily.