imo instant messenger

imo instant messenger is a web-based service with video and voice chat functionality. imo's web messenger and mobile messenger apps let you IM your friends

A single login for all your IM accounts.

imo lets you link all of your instant messaging accounts. When you login to a linked account, you will automatically be logged into all the accounts you have linked. With linked accounts, you only have to enter one login to access all of your instant messaging accounts.
To link your accounts, log in with your pre-existing usernames and passwords. Once logged into multiple accounts, you can link our accounts by clicking the "link accounts" button in the "Accounts" menu.
To unlink an account, hover the cursor over the account you want to unlink and click the “Unlink Account” button

Access here