Detect if Android app has been installed on the device using a mobile web page - PHP and JS

Fortunately, this is not possible, for obvious privacy reasons.

The closest that you can do is in the application, have an activity that has an <intent-filter> for some URL structure, and have a link in the mobile Web site to a matching URL.

If the user clicks the link and the app is installed, the activity will be a chooser option for the user.

If the user clicks the link and the app is not installed, or they choose to stick with their Web browser from the chooser, whatever Web page exists at that URL will be displayed (E.g., instructions of how to download the app).

You can use the PHP imagestring() function to create an image.

<?php
// Create a 100*30 image
$im = imagecreate(120, 30);

// White background and blue text
$bg = imagecolorallocate($im, 255, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 255);

// Write the email address at the top left
imagestring($im, 5, 0, 0, 'test@test.com', $textcolor);

// Output the image
header('Content-type: image/png');

imagepng($im);
imagedestroy($im);
?>

In short, no there isn't a way to determine if an app has been uninstalled.

See my answer to this question which might help:

The feedback service is designed to inform you of devices which have failed to deliver pushes for some time. You should act on the data in there and stop sending pushes to that device. It could take time to get into the feedback service though because it's only really meant to go in there when Apple have deemed that the device has uninstalled your app, or the device is no longer used, or a similar event rather than just the device is out of range at the moment and has no connection to APNS.

Basically, yes you could use the feedback service of APNS but it wouldn't conclusively tell you if a device had been uninstalled. If you need to know this then you're unfortunately going to have to change the way you're going about things as it's impossible to know (at present).