Can heroku free account is enough ?

Of course you cannot know whether it will be free for a lifetime.
Will the company exist for a lifetime? Mine possibly but unlikely for
yours I think. It will remain free only as long as it suits their
business model, which I guess is to provide a free service to the
likes of yourself so that when you come to do a commercial application
you say to yourself 'they gave me good service so I will pay them to
host my commercial app'.

Colin

Thanks a lot for the reply!!

Sukesh

Thanks a lot for the reply!!

Sukesh