Making HDR using a single photo

After (straight HDR not tone-mappped yet)

     HDR or High Dynamic Range imaging is a process of taking multiple photos of a single scene in
different exposure ranges and combining them in post to show all the exposure ranges not usually
captured in normal photos. Usually at least three exposures, the highs, the correctly exposed then one with
the lows. The highs will enhance the bright areas of the photo. The lows will be enhancing the shadows.
 

Before

    HDR photography has created quite a stir in photography world for a few years since it became popular.
Some photographers says its cheating, while on the other side of the fence they say it's just the same as what photographers do on post production. And there are also taking of sides on the pro HDR regarding the overdone HDR's.

You don't have to buy high-end photo editing software

            Complaining about the lack of functionalities, plugins, actions your free consumer grade
photo editor? Well I did. And It always unsatisfied of the presets and always wanting to have more control.
I asked, searched for the best free photo editing software and one stood out.