25% frame-rate improvement! I REALLY like the increased fluidity of the sim in 9.01 thanks to this increase.

Calibration screen for phone tilt! One guy writing a review at the AppStore said he likes to fly on the couch, and wants VERTICAL to represent neutral-elevator: Fly on, couch-dude! Just go to the SETTINGS tab in the interface and set any phone angle as neutral! Now you can relax in bed or on the couch, with vertical being the reference-point for neutral-elevator, or sit up holding the phone in your lap with HORIZONTAL being the reference-point for neutral elevator, or anything in between! Set the center-point as you see fit!

Higher-contrast interface! One person said his eyes are a little weaker these days, so we contrasted the interface a bit more to make it easier for all to see! I managed to do this without making the interface look too harsh, I think.

Power and flaps set for you on the final approach selections. One guy writing a review at the AppStore was rather paniced that he had to move his thumbs 1/4" to set the power and flaps on final.. the horror! So, X-Plane now sets 25% power and flaps automatically when you set yourself up in flight, to be more closely configured for your landing! Kind of convenient.

The interface screens are organized a hair differently... much better I think. This lets volume-control and neutral-elevator control be in their own system-config screen, with a different screen dedicated to setting your location! Kind of nicer organization.