Please help me with Educational Technology pt.3

How to launch an app: steps to be successful? launching an app is a great idea, but it’s not that easy as we supposed to think. the majority of mobile applications don’t generate revenue because companies aren’t ready to be competitive. referring to our experience in successfully building and launching apps we hope to you omit these difficulties. we are going to talk about ideas, marketing, testing your product, its development, distribution and support. you will learn 8 product launch stages to succeed.

Which operating system is a version of linux?

Plz ( which is an example of a good url?