What the app check results mean

Available, taken, invalid, manual, unknown. And why checks are paced.

The results

Available: no account has it. How sure that is depends on the platform, and the app shows it with every free: sure when the platform's own sign-up check said so, otherwise no owner found, with the reason under it.
Taken: someone has it.
Invalid: it breaks that platform's rules. The app suggests the closest valid version.
Manual: that platform can't be checked from outside, have a look yourself.
Unknown: the platform didn't give a clear answer this time.

Platforms change their rules, so always confirm on the platform before you rely on a result.

Checks are spaced out per platform, capped per hour and cached, so nothing gets you blocked and nothing gets asked twice.