Device incompatible with the Play Store app

Some devices, especially a tablet, are not able to download a play store app. Does anyone know what it may be blocking?

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sponte.PortalDeNotas"
    android:versionCode="100"
    android:versionName="1.0.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="19" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.BLUETOOTH"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.VIBRATE"/>
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/icone"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <activity
            android:name="com.sponte.PortalDeNotas.Home"
            android:label="@string/app_name"
            android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity 
            android:name="com.sponte.PortalDeNotas.PortalAluno"
            android:icon="@drawable/ic_launcher" 
            android:theme="@android:style/Theme.Black.NoTitleBar"
            android:screenOrientation="portrait"/>
        <activity android:name="com.sponte.PortalDeNotas.sem_conexao" android:label="@string/app_name"></activity>
        <service android:label="BackgroundService" android:name="com.sponte.PortalDeNotas.BackgroundService"></service>
        <receiver android:name="com.sponte.PortalDeNotas.onBoot">
             <intent-filter>  
            <action android:name="android.intent.action.BOOT_COMPLETED" />  
            <category android:name="android.intent.category.HOME" />  
        </intent-filter>  
        </receiver>  
    </application>

</manifest>