What jailbreak can allow me texting?

So let me explain this. I got an iphone. I can jailbreak it thats not the problem. My parents never gave me a texting plan. So is there a jailbreak that can allow me txting through the imessage app?

Can you still download apps on Iphone 4?

Someone is selling an Iphone 4 for $60. Great deal however, after doing some research I found out that Iphone 4 can no longer be updated.

So can I download apps on it? Especially Apps like Facebook, viber, what's app?

Please answer as soon as you can as I'm going to but it tomorrow.

Iphone 5S screen strange looking rainbow colored line when phone is off. This normal?

Okay so I never saw much about this topic because most people who complained about their screens on iPhone had dropped their phones. I just got this phone this morning and have been using it all day. I noticed a sort of pattern on it when the screen is off like a rainbow colored ripple that curves around and goes from the top of the phone to the bottom. It's only visible when the phone's screen is off and at an angle. Just wondering if this is anything to worry about?

Why don't I have the new emojis on my iPhone 6?

I just bought an iPhone 6 and I don't have the new emojis? Aren't they built into the iPhone 6 models? Why don't I have them?

Added (1). I have version 8.1.2, but in settings, it's asking me to update to 8.4?

Best place to sell water logged iPhone 5s?

Best place to sell water logged iPhone 5s? - 1

Added (1). I have a gold iPhone 5s that has mild water damage to it. It still charges well, and has little to no scratches. The only thing wrong with it is that the home button does not work sometimes. What is the best place I can sell it to for the most money?

Is it normal to have light-specks in your vision?

The best way that I can describe it is like how it looks when you record a video with a cheap camera or phone such as an iPhone 5, except not that extreme. It's all the time, not just in the dark