I'm currently working as a Software Developer on an F-1 visa with my OPT for a company in the US. While I'm working here I want to start a kickstarter campaign to fund my personal project. I should say that I'm not planning to quit my job until I get a Greencard, so I will still be fulfilling my requirements for the OPT-STEM. I have asked Kickstarter if there would be any problems with them about starting a project, they said I'm eligible by their standards to start a project. But my real concern is, am I legally allowed to start a campaign in my name with an OPT-STEM EAD card. I couldn't find a lawyer that has a decisive answer to this, so any help would be appreciated.
Yes you can do that as long as you follow the rules outlined in the other answer about registering your own business.
BUT, you have to keep in mind that once your OPT period ends, it will be illegal (from the immigration standpoint) for you to run your own business (assuming you will get H1b or continue F1), unless somehow you obtain a green card.
Note - This is not a legal immigration advice in any shape or form.
According to this University of Michigan website, one option that might fit is:
Self-employed business owner. Students on a STEM extension can start a business and be self-employed. In this situation, the student must register his or her business with E-Verify and work full time. The student must be able to prove that he or she has the proper business licenses and is actively engaged in a business related to his or her degree program.
but it's shaky.