It saves your time lapse photos in-app (rather than to your camera roll) for you to export to the location of your choice: your photo library (as individual photos), the Glimpse Cloud, or SyncDocs. The latter two store your photos as movies/glimpses; they are free but do require you to have an account.
Insulation works by reducing the transfer of heat by means of a barrier. Unfortunately in most cases the better the insulation the more it costs, so like most things a balancing act is required. To understand insulation you need to know what thermal conductivity, R values and U values are. Thermal conductivity is the measure of how easily heat flows through a specific type of material, regardless of the thickness of the material. The lower the thermal conductivity of a material, the better the thermal performance (i.e. the slower heat will move across a material). See below for some example materials and there conductivity values.
Thermal conductivity, k, is the property of a material's ability to conduct heat. Thermal conductivity is the fundamental property of a material which relates its ability to conduct heat. Heat transfer by conduction involves transfer of energy within a material without any motion of the material as a whole.