Why does my iphone screen keep controlling itself?

So my iphone is in horrible shape, in terms of a broken screen. It's having a hard time responding to touch and I can't type. Also, it keeps opening apps on its own. Someone told me that the screen is pressing up against the digitizer and is acting as if I was touching the screen due to the cracks. If so, can I just replace the broken screen or do I have to buy another phone? I want to wait on the iphone 6 to use my upgrade.

What get's deleted with Battery Doctor app made by KS Mobile Inc. For Iphone?

I recently downloaded the "Battery Doctor- Must-have Battery Management App" App from the Apple Store. Having "Boosted" my memory, i have removed an accumulated 1.7GB of memory and 1.3GB of "junk." It seems every time I open the app, I'm able to free up more space and remove more junk. And it seems to actually be happening as I now have much more space on my Iphone 5c. I'm wondering what is actually being deleted every time I scan my phone for junk and what is happening every time i free up memory… I just want to make sure that nothing important is being deleted and if this app is actually working.

My Instagram app won't load?

I have an iPhone 4, that has almost full storage (I haven't had the chance to delet photos in about a month and it's taking up room), and my Instagram app will come up, sit on my screen for maybe ten seconds and then crash. It's been doing this for about an hour and I've tried turning my phone off twice, charging it, leaving it alone, moving the app around and repeatedly trying to open it. Nothing seems to be working. It was up and running correctly a little over an hour ago, and I'm still getting notifications but it just won't load.
It crashed for the first time when I logged out of my account then back on a few minutes later. It wouldn't load me logging back in and then crashed.

Any solutions? Please?

Help restoring an iPhone that I found please? I can't figure anything out

So today I found an iPhone on the city bus and now I'm sitting at home with it. I've been without a phone for the last few years so I decided to hold on to it. I've tried restoring it with iTunes but it's connected to a Find My iPhone account and I can't find a way around that. If anyone knows one please help me

How to steady a camera with long zoom?

So i'm going to a concert and i bought those high zoom lenses for my iphone 5s. Its 17x zoom and i love it. It works great but what happens is tht its so hard to steady some pictures come out bad. Is there a way i can steady it?

Added (1). ok i have a tripod too but that doesn't help when you're standing. I'm going to concert so ill probably be standing and even if i'm not there won't be a place to set the tripod

Can I Text and or iMessage internationally?

So me and this girl have been talking and we go to different school right across town from each other like 20min apart. She got accepted to do this 3 month international study program where she is traveling with a group all around Europe, and studies and local schools and online. We have been emailing back and forth. I was wondering if we can text and iMessage we both have iPhones. I already sent her a text and it went through as an iMessage and sent another and that one went through as a text message. Will I be charged for the text for international rates? Any advice will help she gets back early June so we're just trying to keep touch so we can pick up right where we left off when she gets home

Thanks any information will be appreciated I just don't want my parents wondering why they got charged for a text to Italy.

Can you restore an iPhone backup from a different computer?

I backed up my phone to my desktop and now my (c. Drive is completely full that i can't restore my phone. I'm having a hard time clearing it to get space, it usually works as I've cleared space and still been able to restore my phone. But this time is extremely challenging. So would it be possible to plug in my USB to a different laptop and still be able to restore my phone?