I have a 2.8 PiTFT which I’ve used on my Pi 1 and just set it up on a Pi 2. I tried to get Adafruit’s FreqShow working with the screen, and it would display, but was unresponsive to any touch inputs. I know touch was working in X Windows otherwise, and had ran through all the calibration tools in the PiTFT setup instructions, so something else was wrong.
Some Googling later, turns out the PiTFT and PyGame (used by FreqShow) works ok on Raspbian Wheezy (which I have on my Pi 1), but not on Jessie (which I have on my Pi 2).
Trick is to replace libsdl with the prior/older version from Jessie – a script to do the replacement is in the post linked about. Ran the script, and now FreqShow works on the PiTFT 2.8 great. Shame there’s no audio out as well, but a cool use for the small screen.