Manage multiple IMAP accounts from 1 webmail interface

I’m using mozilla thunderbird for IMAP access to about 7 email account and I like it to keep it separate because of transparency, different nature of emails etc. and not resend it to one general mailbox. Therefore it would be perfect to have lightweight online IMAP like WebTop or RoundCube client to check for mails on all my mailboxes in one Tab simultaneously…

I know that SOGo already supports it, hope that webtop will add this feature in the future. Folks, how many of you are using multiple IMAP accounts on your mail client?
For me, It might be a great step towards a clientless solution.