When a web page or an application is built for a mobile device, most importantly you have to have the testing done. Testing gives you an idea of what your readers or visitors going to experience when they come and visit your site.
There are plenty of ways in which you can test an Android application.
It is a free and super-fast Android Emulator and is faster than ADT.
Graphical XML layout editor
It is a simple way to do testing for the different layouts.
It is one of the first utilised automated testing tools for software support. It is free Android UI testing tool and is suitable for tests automation. It is also known as Selenium for Android. The test created by this testing tool is written in Java and it is a library for unit tests. The main drawback here is it takes much time and effort and it is unsuitable for interactions with system software. It can also not lock and unlock smartphones and tablets and cannot provide a screenshot.
It is the most popular tool used for functional testing. It is low in level with Robotium. The tests are written in Python and a recording tool is also there. It is done on real devices and it has an API which controls and is connected to PCs or emulators.
The main disadvantage of the mobile app testing tool is that it is necessary to write scripts for each device and the test require adjustments when the user interface of the tested program is changed.
Android Virtual Device (AVD) Manager–
It is available to install as ADT (Android Development Tools). You can view a graphical representation of the layout design and it is certain that the final layout will be identical to the graphical view.
There can be possible device types and configurations, including RAM, screen size, screen resolution and the Android version after using AVD manager. The app can be run on these devices but is slower than a physical Android device. For more information visit: https://developer.android.com/studio/run/managing-avds.html
Buy used devices
A two-year-old flagship can be bought for less than a third of the initial retail price, and mid-range and low-end devices can be purchased at rock bottom prices which is at much cheaper rate.
There are many websites on which you can test the mobile apps.
Firebase Test Lab
It is free up to some features. For more information visit: https://firebase.google.com/docs/test-lab/
It is a virtual device for games testing. For more information visit: http://www.bluestacks.com/
It has a free/demo version. For more information visit- http://saucelabs.com/