Is the Facebook Mobile App that they advertise on Facebook free?

Having troubles with Facebook iPhone app! Help!!?

• I was using my facebook app on my iphone 4 today like normal and i was going through photos and for some reason the photo got stuck on facebook if i went to the facebook home page the photo was covering the home page and would not disappear that is the second time that has happened. So i deleted the app and tried to re dowbload it and it said it downloaded but it is NOT on my home screen anywhere, and when i search for it in my phones search bar it isnt there but when i go into settings and i click notifications facebook is there!? i still get notifications from the app and when the notification comes up i click on it and it takes me to the facebook app like usual but the app Is NOT anywhere to be found on my phone. It wont let me Install the app again as it says it is already installed? But why cant i find it, why doesnt it come up in search. Its really annoying me because i have to use safari which sucks. Any clues ideas would be greatly appreciated.

• Answer:

  seems like there has been some trouble due to conflict of files. i suggest you to restore your iphone software and try installing facebook again. i am quite sure that it will work after you do it.