In order to login easily on Sharesome, we have integrated Twitter as a sign in method. If you don't have an Account on Sharesome, you can easily sign up with Twitter on the Register page. Under the signup form you will see a blue button that says "Signup with Twitter".
If you already have an account on Sharesome, you can easily link your existing profile to your Twitter account. You can do that by going to your profile's menu, where you'll find the "Enable Twitter Sharing" button.
Selecting any one of these will redirect you to Twitter's authorization page. Once there, you have to log into your Twitter account or, if you are already logged in, to authorize the link with you Sharesome Account.