Bitbounce - Charge unsolicited email senders a cryptocurrency fee

7todos - A task board for indie hackers

Swagbucks - Swagbucks is a loyalty program that offers individuals rewards for engaging in various activities. Users can earn reward points for performing Internet searches, purchasing items from affiliated vendors, or completing polls.

Butterfly - Butterfly is the web platform & chat-bots that offer real-time coaching to continuously develop managers based on their team's feedback.

21 Lists - Send and receive targeted, paid microtasks

Todoist - Todoist is a to-do list that helps you get organized, at work and in life.