You need to merge three PDFs: a signed agreement, an invoice and a certificate. The actual work takes 30 seconds, but most PDF sites want you to start a monthly subscription before they'll let you finish.

So I built my own PDF Merge and PDF Split tools on SamToolkit . They're free for 10 pages a day, and if you need more, you can buy a $5 weekly pass: a one-time payment that never renews automatically, so there's no subscription to forget to cancel.

The problem: subscriptions for occasional work

Most people don't merge PDFs every day. They do it a few times a year: when filing taxes, applying for a visa, sending a client a set of documents, or submitting a loan application.

The popular PDF tools are built around monthly or annual plans. Their free tiers work for small jobs, but once you hit a limit, the next step is a recurring subscription.…