There is a lot of "how to do accounting at startups" content which is lacking on the Internet -- maybe something as basic as "how to spend your own money pre-raising funding so you can get reimbursed", and then the basics of accounting for a team of 2-5 with minimal (<500k) seed investment and early revenue.

Just teaching people the difference between cashflow and P&L would be a worthwhile lesson.

If I were you, I'd probably develop a sizable (20-30+) number of standalone free 1-5 page resources on various topics, then offer a service instead of a product (15 minute consultations, phone/skype).

I am not sure how different the accounting rules are in the US vs. Australia vs. elsewhere -- aside from tax, for early stage companies, they're probably fairly universal. I do think helping people set up something like Xero would be useful, since Quickbooks is rather mediocre, and NetSuite is overkill (and the single-entry systems like Freshbooks aren't really worth considering).

In general, sell expertise, give away anything else.