- In all list views (in all apps, by the way): Tap on the status bar at the very top of the screen (e.g. on the time) to scroll to the top of the list.
- On the main rules screen of SmartPlaylist: Tap on "X: N rules" (e.g. "A: 3 rules") at the very bottom to show / hide inactive rules (same as "Show only active rules" / "Show all rules" in the tools menu "⌘")
- In SmartPlaylist's result list: Tap on "SmartPlaylist X: N" (e.g. "SmartPlaylist B: 39") at the top of the list to refresh the display of play count and last played (or the rating, after having changed it in the built-in music app) -- in most cases this happens automatically, but with this trick you can enforce screen refresh.
- On the "Now Playing" screen: Tap on the time already played on the left or on the time remaining on the right of the playback time slider to pause / play the current song.
So now you know.