The first "Aisatsu" is given even before the tea ceremony start.
That greeting is very meaningful and it tells that you're about to have a zen and cheerful moment : drinking tea.
That app : "Aisatsu" try to bring you at home that relaxing moment, aiming you to record the teas you own with their appropriated settings in order to drink the perfect tea every time.
A green Sencha, for an example is prepared very differently from a black tea : if the water is too hot or the brewing too long, the subtils aromas would be destroyed.
If you own a lot of teas like any tea enthusiast, it's almost impossible to remember how to brew properly each tea.
Aisatsu is here to help you remember that and include a timer to make it easier for you to brew the perfect cup of tea each and every time.