How to implement ids.xml file as it shown in Google Developers guide?
<p>I am trying to upload my libGDX game to google play store but although it just took mine 3 days to develop the game I am unable to setup google play services almost for one week now. First of all please excuse my ignorance but I just don't understand this <a href="https://developers.google.com/games/services/android/quickstart#step_3_modify_your_code" rel="nofollow">modify your code</a> section. Don't think I didn't search for it yet again I couldn't understand these:</p>

<p><strong>1)</strong> Open res/values/ids.xml and replace the placeholder IDs. If you are creating an Android game from scratch, you will need to create this file first.</p>

<p>a) Specify your application ID in the app_id resource.</p>

<p>b) Specify each achievement ID that you created earlier in the corresponding achievement_* resource.</p>

<p>c) Specify each leaderboard ID that you created earlier in the corresponding leaderboard_* resource.</p>

<p><strong>2)</strong> Open AndroidManifest.xml and enter your package name in the package attribute of the <code>&lt;manifest&gt;</code> element. If you are creating an Android game from scratch, make sure that you also add the following code inside the <code>&lt;application&gt;</code> element:</p>

<pre><code> &lt;meta-data android:name="com.google.android.gms.games.APP_ID"
        android:value="@string/app_id" /&gt;
   &lt;meta-data android:name="com.google.android.gms.version"
       android:value="@integer/google_play_services_version"/&gt;
</code></pre>

<p>Firstly, I created ids.xml file however, what is this placeholders id's that I should replace? There is no such thing like that. </p>

<p>Secondly my game doesn't have an ID. What is this app_id resource that I should specify? Where am I going to specify it? Is it something like this <code>&lt;item name="app_id" type="id"/&gt;</code></p>

<p>Thirdly, game is maybe too simple so that there's no achievement nor leader board. Do I have to add these things that I really don't know at all?</p>

<p>Lastly, <code>android:value="@string/app_id"</code> gives error. Is it because I am unable to create ids.xml file properly or do i have to add something to strings value?</p>

<p>I just started developing apps for Android. My question is probably too easy that I shouldn't even ask it at the first place. But I believe if you help me with this it would be a fantastic guide for people who just started developing games. Any help will be very much appreciated. Many thanks in advance!</p>