Like almost all of my software, I wrote Organise to fill my own needs and still use it heavily myself.
Occasionally someone has contacted me about problems with calculations if their system preferences are set to format numbers differently from here in the UK (for example, if they're in a country using a comma as a decimal separator and dot '.' as a thousand separator).
But I've never gone through the app and made sure that Organise works perfectly regardless of user number formats. The same thing applies to the sales tax rate (for example, Canada apparently has three different taxes, which Organise hasn't been able to handle).
I had a wake-up call when Organise was put on offer on a popular download site recently. Why people buy software without taking advantage of a free trial I don't know, but they apparently do, and it's very awkward when they find that it doesn't work for them.
It has been a tough task. The code behind Organise is vast now and there are many places where it makes calculations and needs to take account of the user's choice of number format. But I'm just about there.
And to complete a truly international version (version 6!), I've also tried to add the flexibility that's needed for folks to calculate their sales tax wherever they are. Defaults are in line with the UK rules, but as you can see here it's now as customisable as I think it needs to be.