Beeminder? I've seen them mentioned here a time or two, and iirc they use a not ...

		throwanem on April 15, 2022 \| parent \| context \| favorite \| on: Tokyo’s Manuscript Writing Cafe won't let writers ... Beeminder? I've seen them mentioned here a time or two, and iirc they use a not wholly dissimilar "do the thing or lose some money" model.