I have seen this be a huge problem for smaller companies that do not either a) have someone's who is good at their job of following up on invoices or b) an owner to does this themselves.

Like months past due on invoices that are make or break for payroll and at least one time that a company missed payroll over this.

Without knowing much about what you've made beyond the link, I think that there is a need for what you've created.

Any comments or feedback would be greatly appreciated! Also, not sure if possible on HN, but send a message if you are keen to give the product a go! I will post to this thread when the bot is live (hopefully tomorrow)