FYI: Posts here are simply called Posts (officially).
They *used* to be Toots, but it was changed when CoSo forked off from Mastodon.
The user guide still says Toots, but it is outdated.
But right here, right now, under my Settings-Preferences:
Disclose application used to send toots
The application you use to toot will be displayed in the detailed view of your toots