Show app update message to android users when they opened the app
<p>Is there any way that I can indicate my android app users to update their app in PlayStore. <strong>I haven't written any code to "check version number and show an app update message", in my previous app.</strong> What I have known so far that in this situation some solutions could be, like:</p>

<ol>
<li>Play store will fix this issue(by sending push notification) after a new version is updated.</li>
<li>I can send push notifications to the app users to inform them to update their apps.</li>
</ol>

<p><strong>I am new to android app development. I know that this question is not making any sense because the codes are already compiled and I am not be able to do any edit to that code. The app communicate with the server in Json data format. But I am not able to send that "app update" message to the app by using one of the array keys, from server side. If I do, the app gets crash.</strong></p>

<p><strong>So, I am guessing if there any way that I can inform to those app users to update the app (may be via playstore), when they opened that app, in a dialogue box/something, with my custom message and it is not via the push notification message.</strong></p>

<p>Please suggest me the solutions other than those I have mentioned above. If it is impossible, then comment it also. I need to confirm it that what I have known so far is correct. </p>