Professional and short brand name that plays both on the word "up" and "app".
Uppso has only five characters and only two syllables. Two syllable names make popular global brands. Two syllable names are used by established brands like Visa, Twitter and Kleenex.
Uppso.com is a .com domain. Dot com is the most prestigious domain extension. Owning a .com says that you own the word "uppso" online.