I'm currently using SQL server 2008 R2(SP1) and SQL server 2008 (SP3) and the applications using these servers are storing the credentials in a plain text json file. My issue is I need to store user credentials as access is only allowed to authorized users.

How should I go about this? Could I sub out the credentials with the hashed version?
['https://Stackoverflow.com/questions/41768980', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/5537602/']
You can create alert window outside your application by using WindowManager api

[What is WindowManager in android?](https://stackoverflow.com/questions/19846541/what-is-windowmanager-in-android)

Code Snippet

```
WindowManager.LayoutParams p = new WindowManager.LayoutParams(
// Shrink the window to wrap the content rather than filling the screen 
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT,
// Display it on top of other application windows, but only for the current user
WindowManager.LayoutParams.TYPE_SYSTEM_ALERT,
// Don't let it grab the input focus
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
// Make the underlying application window visible through any transparent parts
PixelFormat.TRANSLUCENT);
// Define the position of the window within the screen
p.gravity = Gravity.TOP | Gravity.RIGHT;
p.x = 0;
p.y = 100;

WindowManager windowManager = (WindowManager)getSystemService(WINDOW_SERVICE);
windowManager.addView(myView, p);

```

Add this to manifest

`<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>`

For Auto close message you can use handler to dimiss after delta of time.
make a consistent alarm manager service class, and research on alert.dialogue activity. After displaying message through box check this link below 

[Execute function after 5 seconds in Android](https://stackoverflow.com/questions/31041884/execute-function-after-5-seconds-in-android)

and call finish(); function to close your message box.