Apps downloading to other devices?

This is a little complicated I suppose, but there are three Apple devices (an iPhone and two iPads) linked to my iPod by the same Apple ID. Sometimes when I download something to one, it downloads to the other three as well, and sometimes it doesn't. It's a pain in the *** to have to go through the iPhone and iPads if I don't want something on them every time I download something to the iPod. Is there a way for me to shut this feature off on one device without having to go into the other three?

How to save battery on my iPhone on a long car ride?

Alright, so I'm going from Cleveland to Pittsburgh, and stopping for lunch in between, so figure about four and a half hours, then, I might be going to the Rock and Roll Hall of Fame, and then that night, I'm going to concert and waiting outside for two hours to get a good spot in the pit. The problem? I lost my car charger. My phone battery has been dying rather quickly and low power mode drains the battery quicker. Listening to music drains my battery pretty fast, too. I've turned location services off, I've turned anything that will drain my battery quickly off. Why does it keep running out? How do I save the battery for a long car ride?

Added (1). I can't afford one at the moment.

Added (2). Lmao, I won't die without it. I just want to make memories since this is my first concert, ever.

Can I convert a normal video to time-lapse?

I took a video of me drawing a piece that took a very long time to make. When I finally finished and checked my iPhone, it was a normal video. How can I convert it to a time-lapse?

I've tried doing it on iMovie but it's still not time-lapse, but just quickened a bit…

Which iPhone should I buy? An iPhone 6 or an iPhone 6s?

I personally love iPhone 6s but the chipgate thing made the whole trouble. Now, I don't wanna reget all my life for buying an iPhone with the Samsung chip in it. I don't care if the difference between the two chips is not much but having to know that I've got the bad chip in my phone will obviously break my heart. And I'll be regretting all my life ( beacause I'm not a 16/32 gigs kind of person) so if I buy an iphone 6s it's gonna be a 64/128 gig. Though iphone 6, which I've used for a couple of months (as my dad owns one), doesn't have all those features like live photos,4k videos, 3D touch. And of course 2 gb of ram. Now which chip is get depends on my luck. But I'm afraid to try my luck because you never know when your luck betrays you. What should I do? Which one should I buy? Should I go with an iphone 6 and sacrifice all those features?