Looking at the prosecution history on the USPTO's PAIR, the patent was granted on the first try -- the Examiner didn't cite any reference against it and granted it right away. That's pretty rare (and weighs toward there being novelty here). Also, note this is a utility patent, not a design patent -- so 20 years of a right-to-exclude from the filing date.

The filing date (and priority date in this case) is April 8, 2010. i.e. that's the date someone would need to find prior art that reads on the claims of the patent. (Unless Twitter can establish an earlier invention date -- which would likely occur in the course of an actual lawsuit about the patent; e.g. a Git checkin of the first implementation, or a drawing in a notebook with a date on it).

As for the claims, the two independent claims are:

A method claim: 1. A method, comprising: displaying a content area; receiving input associated with a first command, the first command including a request to scroll the content area; and based on the first command, performing a second command, the second command being independent of the first command.

And a device claim: 20. A non-transitory computer-readable medium having computer-executable instructions stored thereon that, when executed by a processor, cause the processor to perform a method, comprising: displaying a scrollable list of content items, the scrollable list of content items including a plurality of discrete content items arranged chronologically; receiving input associated with a scroll command, the input representing touch-based user input; based on the scroll command, displaying a scrollable refresh trigger configured to scroll with the scrollable list of content items; in response to determining that the scrollable refresh trigger is fully displayed, providing an instruction associated with activating the scrollable refresh trigger; in response to determining that the scroll command was completed while the scrollable refresh trigger was fully displayed, refreshing the scrollable list of content items; and in response to determining that the scrollable list of content items has been refreshed, automatically scrolling the scrollable list of content items such that the scrollable refresh trigger is not displayed.