As a Software Engineer, anything that I create is owned by the company.
Friday, I hit them with my own personal law: I demand to become a partner in this company, or my software will never get completed!
To my absolute amazement, on Monday morning, they offered me voting stock in the company!
Usually, a company will let you get hit in the ass by their front door if you pull that stunt.
Good for you.
Most agreements for contract employees specifically said anything developed by the contractor became the property of the employing company.
Copyright law even has writing/development-for-hire provisions that give the employER, not the hirEE, rights to projects developed by the hirEE during employment.
Disclaimer: All agreements/contracts should be read closely.
I worked for a copy once, as a full employee, not contractual. We were required, however, to sign an agreement. That agreement stated than, if we left the company, they had the right to disavow that we had ever worked for them. (The company developed software for grocery wholesalers and stores; it wasn't secret DOD stuff. lol.) Needless to say, we balked at that provision and refused to sign until that was removed.