Another suggestion for the "Warning" page. Since you already have the "TFR/METAR information out of date", how about a user configurable option advising of time remaining for various selected maps?
I would imagine having a page with all the map products. I could select all or some of these products for the iFly to monitor and tell me that they're out of, or nearly out of date. I know this is available in the menu, but since we have the warning screen anyway, this might add a more widely used or desired function.