Copyright Infringment

Hello, I am Aditya and have had been working in an organization as Business Analyst from past 5 years. During my tenure there, I used to work on enhancement and functionality testing of a Project Management tool which was used In-house for all internal employees. From last 2 years I started working on creating a Project Management tool of my own. Since I'm not a developer so hired a developer who had build the application for me. The application is totally different than what I used to work on in terms of Functionality and UI however the base of both remains the same (Project Management Software) I have recently resigned in the organization and planning to incorporate my Private Limited firm and start selling the same once I'm out of the office. There isn't any Non-competence Agreement signed by me. I wanted to know if there would be any legal issues in this as I started working on it while I was employed with the company (however I did all in my Non-working hours) Also, is there anything else from legalities perspective they can do considering I created similar software which I was given access to (Even though I didn't even looked at the source code but used my logic while building the application) Please advise.