Twitter login app setup
1) Go to https://developer.twitter.com and login (you may need to create an account). Click the Developer Portal menu entry.
2) Currently you will need to request a new App to be setup which is usually quite a fast process. Twitter will request certain details from you but basically you will be requesting just the ability to have a Login wth Twitter app and requiring email address acess.
3) Once you get the approval email click the link they provide. You should see a page like this.
3) Ensure that Enable 3-legged Oauth and Request email address from users are enabled.
4) Add a Callback URL to the URL displayed in the plugin for Twitter. This will be something like https://www.yoursite.com/slpw/plugin_sociallogin/twitterredirect.php.
5) Click Save and you should get the App Id and App Secret that need to be entered into the plugin.