No volume on iphone sometimes?

I've been having problems with the sound on my phone (4G) its temperamental with apps like youtube, IGN, and others. Never had any problem with any game apps. Its annoying because i don't have my headphones on me all the time so does anyone know about this or knows how to fix it?

My Internet is slow on my iPhone?

I have Verizon 3G Internet and every time I'm at school or somewhere the 3G thing on my phone turns into a circle randomly. I have no idea what that means but it's making it really slow. My dad is paying a lot of money for my Internet and it doesn't work well. What should I do?

Which is the dependent and indpendent variable?

Consider the following question: "Which phone is easier to use - the iPhone or an Android-based phone?" What is the dependent variable in this question?
Answer a. Ease of use
b. One of the two phones
c. The question of whether one phone is easier to use than the other
d. The iPhone and the Android-based phone

Added (1). So the independent variable is A or C?

Is this contract for an Iphone 4 genuine?

Is this contract real or a scam, because it sounds kinda too good to be true (15.50 a month):

http://www.chitterchatter.co.uk/iphone/iphone-4-8gb-white-pd-250.php?infinity=gaw~iPhone%204%20Contract%2BUK%2BENG%2BSPART~iPhone%204%20Contract~33025986939~iphone%204%20contract~e

It may be because its only 100 minuites, but is it a good deal?

Idea about a new, iphone apps?

I think i have a great idea about a new app for Iphone, well i think it is a great idea! I don't know how or where to go with this idea, i would like to sell it or try make money from it, Well! Money that is what it is all about, ain't it?

Added (1). Thanks for the first two answers,! Ideas about companies to contact?

IPhone 5 Locked Networks. Buy Contract?

I know that an Iphone 5 locks itself to the network of the first sim used, but. If i took out a contract with vodafone for example, could i, in theory put an ee sim in it first? I want too keep my current EE contract as my personal phone and use my existing samsung with the new contract for business. Would this work?

Added (1). The iPhone 5 is different, and it locks to the first sim used.