Spacebook

Spacebook was a social network.

History
, under the name of the Mistress, assembled many notable women from Earth's history to form MADAM. (PROSE: Girl Power!)

The Thirteenth Doctor also used Spacebook. When Dan Lewis was underwhelmed by the pantomime show to which she and Yaz took him, she tried to find a way to make him appreciate it more through Spacebook; she found a link promising to bring forth "the magic of panto" and used it, not realising that it was very literal, causing real versions of magical beings from various pantos to be transported to the theatre. (COMIC: It's Behind You!)

Behind the scenes
Spacebook is a portmanteau of "Space" and "Facebook".