Invoice Generator (from ProLab) is a minimal, single-page invoicing tool. You fill in business and client details, line items, taxes, and notes in one form, and download a clean PDF — no account needed for the free flow. The output is intentionally plain and ready to attach to an email.

A paid Pro tier (around $6-9/mo) adds saved templates, history, and branding. Compared to full-feature invoicing suites, it stays deliberately small — the use case is "send an invoice in under two minutes."