Why free? Why ask here?
Since you are a "Mobile App Developer in one of the Private software company", can't the company pay for a tool or do research itself.
It surely is not a recommendation for an app developer if he has to ask such questions on a consumer oriented forum. So let me warn our members: don't contact a company called tvisha if you need apps or such.
Can any one suggest me
How to convert website to mobile app for free?