Ionic App not installing in android device

You can follow the steps which are mentioned in the official doc below.

Deploying to a Device

But for me, it didn't work.So I just manually did that as shown below.

1. ionic cordova run android --device

2. Plugged device to the PC using USB

3. Copy the android-debug.apk file to the device (apk path:.. \platforms\android\build\outputs\apk)

4. After that, You have to enable below setting on your Android device

settings --> general tab --> security --> unknown sources (enabled this)

5. After that just double-clicked the android-debug.apk from the location which you have copied.Then your app will be installed on your device.That is it.You can use your app on real device now.

The most probable reason I can think of is that your application is not signed. As Sampath mentioned try to build a debug version and not release version of your application and then install it on your device. You can can use 'ionic run android' and copy/paste manually the output android-debug.apk file to your device.