FearAndArrogance

Don't downvote the person for asking. There is nothing wrong with not knowing.

I can't imagine Laika ever topping Kubo; it feel like a masterpiece to me. Both Song of the Sea and Secret of the Kells are Ghibli / Best Disney Animation / Best Pixar caliber.

It kills me that people would go to Ice Age before these kind of movies.

What makes you different from companies already selling items like this?

http://luxa2.com/productlist.aspx?c=9

I mean what is the difference? Is the point is that this one can still fit in your pocket?

The big drawback of that is not being able to use a case on your phone.

My question was mostly about, why is this more useful than any other power bank. What will make customers buy a sleeve over a normal power bank.

The general advice is python (because it's wide use and ability to do lots of things). But if you want to do web or apps specifically something else might be better.