IANAL, but I'd say that your current employer would have grounds to sue you, since you are trying to sell on your own the same product you are developing at you

IANAL, but I'd say that your current employer would have grounds to sue you, since you are trying to sell on your own the same product you are developing at your company. Even if you have the right to work on it during your free time (and it's not clear that you have that right since you're talking about a competitor product), they might argue that you did some bad work on purpose at your job in order for your product to be better - lawyers could argue lots of things... The standard procedure to work on something outside of your job is to get a written agreement with your employer.