Ask HN: Older HNers, would you like to see an annuity replication tool?

I was thinking of creating an informational tool; initially for the UK but also for the US; to replicate the terms of an annuity with a set of bond ladders (bonds with different maturity dates).

It'd allow you to create your own annuities, possibly at much better value than the retail market offers. I.e. put in annuity cost, life expectancy and annual pay out, etc and it'd chug out the closest matching bond portfolio with a similar or better payout structure and value.

I wanted to make it free for us older folks; as a informational public service; but I wasn't sure if it'd be appreciate or used.

What do you think? If I build it, will they(you!) come?