The launcher with its Holo tabs and the icon style look more like Android 4.something (I to K) to me, by the way. Android 5 (L) was the first Material Design release (the one[1] that had actual coherent principles behind it).
Yeah given the holoyolo look it's almost certainly ICS or jelly bean. I think kitkat's launcher looked a bit different, it didn't have the tabs: by then they had moved from tron blue to white.