I can't download certain apps on my iPhone?

I accidentally deleted one of my music apps from the app store, and I paid 2 dollars for the app, when i searched for it in the app store instead of it saying FREE, it says Open, I click open, it asks for my apple password, and nothing happens. This happens when I try to update some apps too. The only thing I can think of is to download it through iTunes, I tried, but it says I have to pay money for it again, and I'll lose all my music from the music app that I had on it. I tried resetting, I even searched google for answers, but nothing helps.

My Iphone 5s touch ID option isn't there anymore?

Ok so i had my iphone since christmas and the touch id worked just fine then a month later the option isn't there anymore and i have done all the steps to everything so what should i do please help i don't want to have to get a new one!

How to lock apps like Instagram?

My friends keep using my iphone 5c on the bus and putting embarrassing stuff on Instagram or texting people I love u how can I lock apps to make them have to use a password to do that

Background on my iPhone won't change?

I had to reset my iPhone and now when I try to change the wallpaper it won't work. I turned it on and off and tried everything I know and it won't work.

How to remove screws on bottom of iPhone 4S?

I know, they are something like pentalobe screws, but I don't have the tool and don't want to wait for it to ship in, so does anyone know how to get the screws out without the screwdriver?