Ah! That makes more sense!
The "bottom of the screen" is called the "Taskbar", and you can "enhance" you app on it with the NotifyIcon: NotifyIcon Class (System.Windows.Forms) | Microsoft Docs
Drag one from your toolbox onto your form, and give it an appropriate name: "appIcon" in my case. You can then set it's properties dynamically in your app:
private void FrmMain_Load(object sender, EventArgs e)
if ((ModifierKeys & Keys.Shift) == 0)
appIcon.BalloonTipIcon = ToolTipIcon.Info;
appIcon.BalloonTipText = "Waiting for URL";
appIcon.BalloonTipTitle = "Load image from URL";
appIcon.Text = "Waiting for image URL ...";
Have a play with it, you'll get the idea!