Android API Guides---App Manifest <uses-feature>

For example, if your app requires portrait orientation, you should declare <uses-feature android:name="android.hardware.screen.portrait"/>so that only devices that support portrait orientation (whether always or by user choice) can install your app. If your application supports both orientations, then you don‘t need to declare either.

Both orientations are assumed not required, by default, so your app may be installed on devices that support one or both orientations. However, if any of your activities request that they run in a specific orientation, using the android:screenOrientation attribute, then this also declares that the application requires that orientation. For example, if you declareandroid:screenOrientation with either "landscape","reverseLandscape", or "sensorLandscape", then your application will be available only to devices that support landscape orientation. As a best practice, you should still declare your requirement for this orientation using a <uses-feature> element. If you declare an orientation for your activity usingandroid:screenOrientation, but don‘t actually requireit, you can disable the requirement by declaring the orientation with a <uses-feature> element and include android:required="false".

For backwards compatibility, any device running a platform version that supports only API level 12 or lower is assumed to support both landscape and portrait.

When declared as required, this indicates that the application is compatible with a device only if it offers an emulated touchscreen ("fake touch" interface), or better. A device that offers a fake touch interface provides a user input system that emulates a subset of touchscreen capabilities. For example, a mouse or remote control that drives an on-screen cursor provides a fake touch interface. If your application requires basic point and click interaction (in other words, it won‘t work with only a d-pad controller), you should declare this feature. Because this is the minimum level of touch interaction, your app will also be compatible with devices that offer more complex touch interfaces.

Note: Because applications require theandroid.hardware.touchscreen feature by default, if you want your application to be available to devices that provide a fake touch interface, you must also explicitly declare that a touch screen isnot required by declaring <uses-feature android:name="android.hardware.touchscreen"android:required="false" />

When declared as required, this indicates that the application is compatible with a device only if it supports touch emulation for events that supports distinct tracking of two or more fingers, or better.

Unlike the distinct multitouch defined byandroid.hardware.touchscreen.multitouch.distinct, input devices that support distinct multi-touch with a fake touch interface will not support all two-finger gestures, because the input is being transformed to cursor movement on the screen. That is, single finger gestures on such a device move a cursor; two-finger swipes will result in single-finger touch events; other two-finger gestures will result in the corresponding two-finger touch event. An example device that supports distinct multi-touch with a fake touch interface is one that provides a trackpad for cursor movement which also supports two or more fingers.

When declared as required, this indicates that the application is compatible with a device only if it supports touch emulation for events that supports distinct tracking of five or more fingers.

Unlike the distinct multitouch defined byandroid.hardware.touchscreen.multitouch.jazzhand, input devices that support jazzhand multi-touch with a fake touch interface will not support all five-finger gestures, because the input is being transformed to cursor movement on the screen. That is, single finger gestures on such a device move a cursor; multi-finger gestures will result in single-finger touch events; other multi-finger gestures will result in the corresponding multi-finger touch event. An example device that supports distinct multi-touch with a fake touch interface is one that provides a trackpad for cursor movement which also supports five or more fingers.

By default, your application requires this. As such, your application is not available to devices that provide only an emulated touch interface ("fake touch"), by default. If you want your application available to devices that provide a fake touch interface (or even devices that provide only a d-pad controller), you must explicitly declare that a touch screen is not required, by declaringandroid.hardware.touchscreen withandroid:required="false". You should do so even if your application uses—but does not require—a real touch screen interface.

If your application does require a touch interface (in order to perform touch gestures such as a fling), then you don‘t need to do anything, because this is required by default. However, it‘s best if you explicitly declare all features used by your application, so you should still declare this if your app uses it.

If you require more complex touch interaction, such as multi-finger gestures, you should declare the advanced touch screen features below.

Subfeature. The application uses SIP-based VOIP service on the device.

This subfeature implicitly declares theandroid.software.sip parent feature, unless declared with android:required="false".

(See Special handling for Bluetooth feature for details.)