You need to take your employment contract to a lawyer and get legal advice before doing anything. Depending on the contract, you may or may not have rights to what you developed in your side project, especially if you are a salaried employee. In my case, my employer owns all IP I develop while in their employment. Happily, my employer has no commercial interest in the code I develop to automate my data analysis and management permits me to distribute it under an Open Source license. They understand the value both they and I receive from a collaborative community of analysts. By the way, each year I must sign a statement that I have no conflicts of interest and if I suspect I might have one, I must disclose it to management.