Developing with Salesforce

Username/Password Service Accounts

If you've selected Username/Password Service Account for your runtime authentication strategy, you'll need to update app/web.config with the Username, Password and Security Token. For more info: How to get your Security Token.
Also, you will need to edit the SalesforceService.cls file and remove the error compiler directive instructing you to add the username, password and optional security token.

You can also Set Trusted IP Ranges for Your Organization to avoid having to use the user security token.