Programs for writing applications for Android on Mac?

Question

Android

Good day!
I thought about learning programming for Android devices.
Most manuals somehow omit the moment,
and what kind of applications are actually needed for development, especially in MAC OS X.
I found mentions of cocos2d, Tasky, Xamarin, Eclipse, even Bitrix has its own constructor,
where to start and what is needed first pores?

Answer 1

What does drop down mean?
developer.android.com/intl/ru/develop/index.html

Answer 2

depending on what you write, if native applications, then Android Studio or IntelliJ IDEA is best