Most invoice tools want a monthly subscription. This one doesn't. Quote & Invoice Builder is a single HTML file that runs in your browser. Build a professional quote, convert it to an invoice in one click — all your data carries over automatically. Features: 4 design styles · logo upload · PAID stamp · payment details · auto-numbered references · discount & tax · multi-currency · save/load JSON · no account needed. One-time purchase. Your data stays on your device. Forever.