Android application not installed error
<p>This old chestnut again, 
After a lot of searching the best thread I found on this is  <a href="http://stackoverflow.com/questions/4226132/application-not-installed-error-on-android">&#39;Application not Installed&#39; Error on Android</a>
In my case I  have checked all the fixes mentioned but still have the problem when I try to install the unsigned APK file. 
The app runs fine on my phone when I install it from Eclipse,  but when I put it on google drive and then point my phone to the APK I get the error above.  I have a Note 1
I have uninstalled the old app, reset my phone etc but no luck.  It worked fine for me until today,  I would just put the APK on google drive and install it from there and it worked each time,  just stopped working today and I have changed nothing.
I have both signed and Unsigned versions of the APK</p>

<p>Here is my manifest file</p>

<pre><code>        &lt;?xml version="1.0" encoding="utf-8"?&gt;
    &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.app.nquizitive"
        android:versionCode="1"
        android:versionName="1.0" &gt;

        &lt;uses-sdk android:minSdkVersion="8" /&gt;

        &lt;supports-screens 
        android:largeScreens="true" 
        android:normalScreens="true" 
        android:smallScreens="true" 
        android:resizeable="true" 
        android:anyDensity="true" /&gt;

    &lt;uses-permission android:name="android.permission.INTERNET" /&gt;

        &lt;application
            android:icon="@drawable/ic_launcher"
            android:label="@string/app_name" &gt;
            &lt;activity
                android:name="com.app.nquizitive.StartupActivity"
                android:label="@string/app_name" android:screenOrientation="landscape"&gt;
                &lt;intent-filter&gt;
                    &lt;action android:name="android.intent.action.MAIN" /&gt;

                    &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
                &lt;/intent-filter&gt;
            &lt;/activity&gt;
        &lt;/application&gt;

    &lt;/manifest&gt;
</code></pre>
