This article assumes that you have a project setup in Unity and would like publish it onto an Android device. It will go through the setting up of the Android SDK.
Android, compared to iOS is a dream for development. For one, you can do it on a PC or a Mac.
Head over to the Development portal for Android, right here, and then hit the big “Download the SDK” button you see. It’s a large file so go ahead and grab some coffee/tea/beverage of your choice.
Once it’s downloaded, un-zip the file and inside it you will find a folder called “sdk“, now open that to find “tools“, then run the file “android“. Either Terminal (Mac) or Window’s command prompt will open up with some text, then eventually the “Android SDK Manager” will open up.
Under the latest Android API (Currently “Android 4.2 (API 17)“) you will see the “SDK Platform” un-checked, just check that and then press “Install (X) Packages…” (Where X is the number of packages you selected to download)
Now for the difficult bit: telling Unity where the SDK is.
Open up Unity and navigate to “Unity > Preferences…” or “Edit > Preferences…” (Mac and Windows respectively). A window will open up with a button for “External Tools” on the left hand of it. Click that.
You should see the “Android SDK Location” textbox, click that and navigate to where you unzipped the files originally and click on the “sdk” folder, then press “Choose”
Setting the Bundle ID and Converting to Android
Load up your Unity project, Press File > Build Settings and select Android then press “Switch Platform“. Your Unity project is now an Android project.
Finally, press “Player Settings” and in the Inspector enter in the “Bundle Identifier” section (Under Identification) and enter the identifier you want to use in the reverse-domain style.
Go, Go, Unity!
Now if you Build and Play, it will push to any Android device automatically if it’s connected to your machine.