These are code names for Android releases, and are well known throughout the Android community. Your developer should be familiar with them. Ice Cream Sandwich was Android version 4.0 (API level 14) released on October 18, 2011. KitKat refers to Android version 4.4 (API level 19), released on October 31, 2013.
This question is really to weed out the beginners who may not be as familiar with the different Android releases and that changes within each. You really want your developer to be in tuned to the Android updates so they know what’s possible, how to best implement what you are asking, and where things are headed in general.