Nüdge Theory automates payment reminders for freelancers and independent professionals tired of chasing clients for money. Set up a reminder in under a minute: enter the client's email, invoice amount, and due date. Nüdge Theory sends polite, professional reminders before and after the due date on a schedule you control. Reminders stop automatically the moment an invoice is marked as paid. Unlike invoicing software that treats reminders as an afterthought, Nüdge Theory does one thing exceptionally well. It works alongside whatever invoicing tool you already use: FreshBooks, Wave, QuickBooks, PDF invoices, or anything else. No switching, no lock-in. Features include custom reminder schedules, professional email templates, one-click mark as paid, payment insights to identify late-paying clients, CSV export, and bulk actions for managing multiple clients. Built for any freelancer or independent professional who invoices clients and wants to get paid on time without damaging client relationships.