Freelancers send invoices and still guess what to reserve for tax. The Freelance Tax Set-Aside Kit is a Google Sheets CSV + Notion pack: mark invoices Paid/Unpaid, pick a country tax profile (KR 3.3% withholding plus year-end buffer, US quarterly planner) and see the amount to set aside. $29 one-time. Estimates for planning only, not tax advice.
Freelance income arrives unevenly and I kept under-reserving for tax, so I built a simple sheet that suggests the set-aside on each payment.