Basic web app:
1) box to enter text (Text above this box says: 'What do you want to accomplish today?')
2) box to enter e-mail. (these should be saved).
Once the user clicks submit, he/she gets the message: 'Go to work, we will check your progress'.
8 hours later the users gets a mail that states the text and asks if the task was completed.
If the user selects yes: go to a specific link
If the user selects no: go to specific link + He/she should receive the same mail the next day (24 hours later).
Should be possible to implement in Tumblr webpage by copy-pasting the code. It should be possible to get an overview of the mail addresses of the people that used the service.