Do I Need an Account?
No. There is no sign-up, no email required, and no login.
There is no account. Download it, open it, point it at a folder. Nothing asks who you are, because nothing needs to know.
Premium is a one-time purchase, unlocked with a code, so there is still nothing to log in to afterwards. It keeps working if the company disappears.
It runs on your own computer and is free for your first 500 photos. Unlimited photos is $9.99 once, on macOS, Windows and Linux.