Per discussion in various bugs (bug 59807, bug 61737, bug 53879, bug 47658) and various threads onwiki, we would like to have a limited Undo feature for "Thank".
The main difficulty to solve, is that currently a 'Thank' will instantly send an (email/echo notification) to the target.
Therefor, some sort of backend delay-mechanism is probably needed,
plus a frontend indication for the Thanker that "undo is possible for x seconds" or "sending Thank in x seconds. Undo?".
30 or 60 seconds have been suggested previously.
On Desktop, this would replace the current Confirmation-step, from the history-page and diff-page. It would also bring consistency to the Thank process in Flow posts (which currently have no confirmation-step).
On Mobilefrontend, it would solve the problem of mis-clicks, without having to implement a confirmation-step.)
 search for 'undo', 'confirm', and 'remove', at https://en.wikipedia.org/wiki/Wikipedia_talk:Notifications/Thanks