How can I find if a particular package exists on my Android device?

Kotlin

fun isPackageExist(context: Context, target: String): Boolean {
     return context.packageManager.getInstalledApplications(0).find { info -> info.packageName == target } != null
}

Edit: Extension Function

fun Context.isPackageExist(target: String): Boolean {
     return packageManager.getInstalledApplications(0).find { info -> info.packageName == target } != null
}

We can check like this:

 if(getPackageManager().hasSystemFeature("android.software.webview") == true && isPackageExisted("com.google.android.webview")) {
            if (Constant.isNetworkConnected(Activity.this)) {
                 //Your Intent 
            } else {
                Toast.makeText(getApplicationContext(), resources.getString(R.string.internet_error), Toast.LENGTH_SHORT).show();
            }
        }   else
            {
                Constant.showDialog(Activity.this,"Please install the webview");
            }
    }

Make method for package check ! this credit goes to "Kavi" https://stackoverflow.com/a/30708227/6209105

public boolean isPackageExisted(String targetPackage) {
    List<ApplicationInfo> packages;
    PackageManager pm;

    pm = getPackageManager();
    packages = pm.getInstalledApplications(0);
    for (ApplicationInfo packageInfo : packages) {
        if(packageInfo.packageName.equals(targetPackage))
        {
            return true;
        }
}
return false;

}

You can use pm.getPackageUid() instead of iterating over the pm.getInstalledApplications()

 boolean isPackageInstalled;
 PackageManager pm = getPackageManager();   
 int flags = 0; 
        try 
        {   
              pm.getPackageUid(packageName,flags);               
              isPackageInstalled = true;    
        }   
        catch (final PackageManager.NameNotFoundException nnfe) 
        {   
            isPackageInstalled = false; 
        }                   
 return isPackageInstalled;