On this page
Start page
The page new tabs open on: your sites, a clock, a search box and a wallpaper.
Your sites
The tiles are the sites you added and nothing else — derp does not fill the page from your browsing history. Add site puts one there; right-click a tile to pin, dismiss or block it.
Dismiss simply takes a tile off. Block also remembers the address so it is not offered again, and blocked sites can be brought back from the settings panel.
Wallpapers
The page ships a set of derp wallpapers and picks one per session; you can supply your own image instead. The same wallpapers sit behind first-run setup.