[Java for Android App Development] mantlabs:
IDEs:

Android Studio (

Officially Recommended

- Works on Windows, Linux and Mac)

Eclipse ADT Plugin (Deprecated - Works on Windows, Linux and Mac)

Requirements:

Java SDK 8 Installed.

Knowledge requirements to study the tutorials:

Java SE (Oracle Tutorial, tutorialspoint Tutorial)

Tutorials:

Official Android Development Page

Official Android Development Training

Build your first app (Official Android Development Training)

Official Android Development Guide

Android Studio Tips and Tricks

I want to study tutorials via Articles:

vogella Android Introduction

vogella General Android Development

mykong Android

tutorialspoint Android

I want to learn the OpenGL ES for Android:

learnopengles (Uses OpenGL ES 2.0)

Android Development OpenGL ES Guide

Android Development OpenGL ES Training

Activity - Fragment Lifecycles

Libraries (more useful Java Libraries):

AndroidPlot (Library for Plots, Graphs, Lines and Charts for Android) [Free, check the License, usually Apache]

kSOAP2 (SOAP Client Library for Android) [Free but check the License]

Retrofit (A type-safe REST client for Android and Java) [Free but check the License]

Google VR SDK (old name Android Cardboard SDK) ( Overview - What is Cardboard - How Cardboard Works - Cardboard Java API - Cardoard Unity3D Guide ) [Free but check the License]

iText (A PDF File Creator-Reader-Manager for Android) [Free for open-source use, but requires you to purchase a license for commercial use - see Pricing]

Material Design - Colors - Themes (References):

Official Google Color Pallete

Material Design Colors

Material Design for pre-Lollipop Devices

Color Picker

Material Design Icons:

Google Material Icons (free, check the license, usually Apache)

Material Design Icons (free, check the license, usually Apache)

Google Material Icon Guidelines

SDK Versions History:

Oreo 8.1.0 API level 27

Oreo 8.0.0 API level 26

Nougat 7.1 API level 25

Nougat 7.0 API level 24

Marshmallow 6.0 API level 23

Lollipop 5.1 API level 22

Lollipop 5.0 API level 21

KitKat 4.4 - 4.4.4 API level 19

Jelly Bean 4.3.x API level 18

Jelly Bean 4.2.x API level 17

Jelly Bean 4.1.x API level 16

Ice Cream Sandwich 4.0.3 - 4.0.4 API level 15, NDK 8

Ice Cream Sandwich 4.0.1 - 4.0.2 API level 14, NDK 7

Honeycomb 3.2.x API level 13

Honeycomb 3.1 API level 12, NDK 6

Honeycomb 3.0 API level 11

Gingerbread 2.3.3 - 2.3.7 API level 10

Gingerbread 2.3 - 2.3.2 API level 9, NDK 5

Froyo 2.2.x API level 8, NDK 4

Eclair 2.1 API level 7, NDK 3

Eclair 2.0.1 API level 6

Eclair 2.0 API level 5

Donut 1.6 API level 4, NDK 2

Cupcake 1.5 API level 3, NDK 1

(no code name) 1.1 API level 2

(no code name) 1.0 API level 1

Changes about Android Versions (for Developers)

Android Dashboards (here you can see the

platform versions

,

screen sizes

and the

OpenGL versions

of the devices that access the Google Play store)

Seminars - Webinars

Collection of Guides about Android Development (on the XDA forum)

Explanation of the most popular Licenses usually used in libraries (IT'S NOT A LEGAL ADVICE. IT'S JUST A GENERAL EXPLANATION. FOR 100% ACCURACY PLEASE CONSULT A LAWYER)

I will try to keep this post updated, as much as I can. If you find anything outdated or any errors, or you want to add anything to this post, or report a broken link, just let me know via Private Message :)

I will be adding any good tutorials I find from the web here.

NOTICE:

Some of the tutorials above use the Eclipse IDE and not the Android Studio (the recommended one). This does not effect the general Android Development knowledge and techniques that you learn through these tutorials. Only the Android Project structure (small changes) and some other advanced mechanisms (such as Gradle that Android Studio uses) are different, and these differences do not affect the general Android Development principles!

[All the above links have been checked on 10th March 2018]