Is posting via app on facebook bad ?

I want to use my PHP skills to write a small script that automate posting on my facebook page using an app but I've read somewhere that using a 3rd party app to post is bad, because it will be seen by less people

Is it true ? and if yes does anyone know about a php script that post directly to facebbok without using any apps ?

I already know about the other tools available for sale, but I don't want to waste money because all I need is a simple task