I will make it easy for you....The point in tagging your article is to get visibility according to your post content. Support you write on space and tag this fitness app when your actual motto of writing is lost because your article is not at all related to the tag that you are using.

And @actifit rewards the actifit articles....this rewarding is done by searching actifit tag. And they only want to reward actifit posts....Hope you understand.