The app structure in Facebook is designed to expose Tokome to new social circles all the time, so it should be a very inviting logo, a bold one that is hard to miss (hard to miss doesn't say that it should be outrages...) .
You can use a webcam illustration in the logo, but only if you feel that it's a must for your concept.
The logo should have a second version (trimmed or scaled) that we will be able to use in the Facebook index (75*75), and in icons (16*16).
It might be a good idea (not a must though) to have an illustrative logo, like the (yet ugly) illustrations we have for the stage designs (YouTube On Webcam, Webcam On YouTube etc.), an illustrative logo might help users to understand what Tokome does right from the Facebook indexes, even before they enter the app.
** Update: We like warm colors.
Let's try to avoid the plain Arial/Halvetica font for the word Tokome.
*** Update: users should be able to understand that Tokome brings the new concept of "recording and sharing video-in-video" in Facebook.
Good luck, and thanks for your precious time.