Camera use is optional, don't disallow install on camera-less devices.
See right side pane at
http://developer.android.com/guide/topics/manifest/uses-permission-element.html

diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index d020d9d..1b45bf1 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -8,6 +8,7 @@
 	<uses-permission android:name="android.permission.INTERNET" />
 	<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 	<uses-permission android:name="android.permission.CAMERA"/>
+	<uses-feature android:name="android.hardware.camera" android:required="false" />
 	<application
 		android:icon="@drawable/icon"
 		android:label="@string/app_name"