This is slightly tricky. In short, no. But you can greatly improve.
I have taught many students for a number of years now and just like learning to master anything, it takes time and persistence.
You'll find that many who do speak like a native have been learning from a young age, when you can adapt a good accent, without your mother tongue/ accent coming through.
The issue with learning online is that when you have a teacher or helper in front of you, they can help correct you there and then and can give you pointers on how to improve the pronounciation of the word or words you are having difficulty with. Online cannot offer this.
Of course having lessons is expensive, but as much day to day interaction with Native's will help improve with this a lot (and for free!)
When I was learning German and Polish, I got many compliments for my accents. What helped me achieve this was by listening and imitating what I had heard....Which can come across as racist and offensive if you are doing a German accent in English talking about 'Oh yeah, mine frauline, she like mine schwantz. Gut time'...so be careful with that :)
Now one issue you will have is that in the Native English world, there are too many accents, but films can help greatly with this as they generally have a standard of clear understandable English.
So, if you really want to develop at home, watch some youtube videos or movies and have your mobile recording what you say. Playing this back should help you enhance your accent, but this will never work as a long term fix in obtaining a Native accent, I'm afraid.
Only being out in the real world will help you achieve this.
