I'm not sure what you mean by "not getting fractions of an inch". Can you give some examples of =i2s() output and what you would want the output to look like?
It's a free add-in, so you get what you paid for. It only converts for denominators that are EXACTLY powers of 2, even down to 1/256, so even 0.9999999/256 results in a decimal, rather than 1/256
Free or not, I think it is pretty good, but then again, I wrote it.
I've put a lot of thought into what the correct result should be when converting non-fractional measuraments like "0.9999999/256" and I think returning an ugly but correct answer is preferable to giving a neat-looking, but incorrect answer.
If all you really want is an aproximation anyway, you could always fix-up the "0.999999999" first by running it though a round() or int(). At least this way you are explicit stating that you want an aproximation rather than an exact answer.
But believe me, if you can think of a better and more consistant way to handle this issue, I am all ears!
I understand of course it's a free plugin I was just trying to understand how it works and now I do.
I am an architect (originally from australia now in the US) and until now have worked exclusively in mm.
The software package we use (Catia) spits out data to spreadsheets in inches however the contractor wants the information in feet, inches and fractions of inches so now I understand what it is the InchCalc addin is doing I can apply a rounding factor to my data to ensure it is in the right format.
Obviously building tolerances are very different to those in the aerospace industry.