Figure it Out was a piece of Windows software I wrote and sold from 2003. It reconciled invoices to payments.
That description makes it sound duller than the problem actually is. A client pays you one lump sum covering some unknown handful of the invoices you've sent them. The remittance advice is missing, or wrong, or it's a bank transfer with a reference that means nothing. You have forty open invoices and one number, and you need to know which invoices that number is made of.
The site put it plainly at the time: "you must have a total which you are aiming for and a list of sub values, some of which may add up to your target total." That's the subset-sum problem, and it's why doing this by hand means somebody loses an afternoon to a spreadsheet, adding combinations up until one of them lands. The software did it instantly, which is where the claim on the front page came from — 1000% faster than doing it manually.
It sold to real businesses. Two of them let me quote them on the site: an accountancy group, and a firm of solicitors who reckoned it saved them seven hours a week.
There was a free demo you could download, and later a version you could log into and try in the browser before buying — which in 2003 meant classic ASP, an access database and a lot of hand-written HTML.
The site is long gone — the domain lapsed and became something else entirely around 2010 — so there's nothing to link to but the archive:
- figureitout.net in February 2007, the version above
- the original 2003 design, chrome wordmark and all