Automatic Scrolling to the Top of the Timeline in Twitterrific (iOS and macOS)

Can I make the timeline automatically jump to the top at refresh?

Yes, enable the "Keep Timelines Pinned To Top" option. This may not always be what you want, however, and there are quick ways to jump to the top of your timeline: On iOS, you can tap the device's status bar (with the time) to scroll to the top instantly. On the Mac you click the icon of the currently selected tab to toggle up to the top of the timeline (and back down) if you wish. You can also press the Home key on both platforms to jump to the top as well.