Needing to work in a collaborative android project would require some version control and project sharing. Most of the time this happens within a local network at the office. Git offers various methods to do this, being using github the most common one, but if you feel like you don’t want to share your work with the wold, or you don’t want to be paying for a private membership, or simply the online thing is not the right approach, or you like instant pulling and pushing, or you don’t want a headache messing with SSH and windows services, you could do this within your already working network, skipping the need of any service setup or online service registration.