Without an account you get everything free: the Slack inbox, your own packs and season choice included.
Pro (₩1,900 / month in Korea, $2 elsewhere, taxes and fees extra) unlocks official premium packs, grass card SVG, animation and share link, usage insights, and 3 devices.
Signing up starts a 14-day trial right away (once per email, no card).
The app signs in with a code from its "Devalley account" dialog, approved at /device.
Manage, get receipts or cancel under "Manage subscription" (Paddle) on My page. After cancelling, Pro stays until the period ends; then only Pro features lock and your data stays.
What leaves your computer: only when signed in, the sign-in token, a device id and plan checks; only when sharing is on, the grass card summary. Sessions, the inbox and Slack tokens never do.
Devalley