(WebBrowser1.Document.GetElementById("id").SetAttribute("value", TextBox1.Text)
TextBox1.Text= WebBrowser1.Document.GetElementById("id").GetAttribute("value")
<dt class="col-sm-3">App Name</dt><dd class="col-sm-9" id="app_name">Hello</dd>
TextBox1.Text= WebBrowser1.Document.GetElementById("app_name").GetAttribute("value")
TextBox1.Text = WebBrowser1.Document.GetElementById("Id").InnerText