The following post is made to explain one feature that I added on my previous development. I have added the possibility to get the value of a contribution. I'll explain more precisely of a contribution is estimated.

After the first release of this tool, @Someguy123 tells me that could be a good idea to display the repartition of the reward between author and curators. But at that time, I only wanted to show the true value of a reward (and not a contribution).

Now, I'm little bit more confident with steemjs and I can work with more data.

Show me my post reward

Contrary to what one might think, an author gets more than 75% of the reward of a post.

From the official @steemitblog release:

all curation rewards earned by voting in the first 30 minutes after a post is made will be shared with the author. If you vote immediately after a post is made, then 99.94% of the curation reward will go to the author. If you vote after 15 minutes, then 50% will go to the author. Any votes made 30 minutes or later 100% will go to the curator. This only applies to the curation rewards. The author still gets at least 50% of the total rewards.

And according to this information, I would like to estimate the author reward based on it. it's pretty easy because the API and the steem.api.getContent() function gives all informations.