Once you’re done with building your team and have an idea to develop, it’s time to create an agreement with the participants and set up the company.
Real companies usually create a shareholder agreement that specifies many different aspects (rights, obligations, selling shares, leaving the company etc) and is quite detailed.
Purpose of the agreement is to make sure everyone commits to work for the company and participants feel that they are all treated fairly. This kind of agreement are a lot easier to do before setting up a company that afterwards.
In JA Startup we recommend you to create a simple agreement with basic rules and obligations.