app development using linux

So I am new to app development and I'm wanting to make an app that my small company can use to track logistics. I am working through a course on Xcode 7 and Swift 2 to learn how to do the basics in Xcode. I'm setting up a server to run everything off of in Linux. I just read about a program called LiveCode in which you can make apps in Linux Code and it will run without the need to change the code across all platforms (Mac, Windows, Linux, Android). I think this would be an easier method to go with because some people have iOS devices and others Android.

My question is will Apple accept an app to it's app store that has not been developed in Xcode? If it is not in Swift 2 language?

I'm no programmer by any means so this will be a lengthy project I'm undertaking but I think it will be a lot of fun and I will learn a lot along the way.

Thanks for you help guys and gals!