Did my S4 die? Need assistance soon please!

A

AC Question

I was skyping on y Galaxy S4 one time with my friends (I know it wasn't a good idea but it was all I had at the time) as i was skyping the phone started doing some odd things, the audio got EXTREMELY MUDDY to the point to where it was almost impossible to make out a human was speaking. This problem corrected itself in a few minutes, then it got worse. While i was skyping a pop up kept appearing asking me to install an app (I don't remember the name of the app it wanted me to install) the app apparently was, from what i could tell a very bad knock off of the google play store. I kept closing it out, but by complete accident I tapped "Yes" the app immediately installed and then my phone started bugging out. The app would suddenly appear then close itself out AND the battery wouldn't charge. As far as I know when I charged it the percentage NEVER went up it continued to go down. But when I put the battery into my brother's phone it showed that the battery did charge. after that i put the battery back into my phone and now the phone won't even turn on. The grey dead charging battery graphic would appear, the phone would vibrate, next the graphic would disappear and it would do it again. It constantly does this no matter what I do in an infinite cycle. My friend believes it is the charging port, but i think it is either the software or the battery, please help I have tried all I can without purchasing a new phone.