Tapping the top of the screen scrolls to the top of the page.
--- On iPhone ---
1. Start iLunascape
2. Tap the status bar at the top of the screen to display the address bar
3. Tap the settings button (the wrench icon) on the right
4. Switch "Scroll to Top" to "ON"
--- On iPad ---
This feature is always ON in iLunascape for iPad, and cannot be disabled.