▁to ▁create ▁a ▁project ▁for ▁either ▁the ▁i Pad ▁or ▁iPhone . ▁After ▁a ▁user ▁created ▁a ▁few ▁screens ▁for ▁a ▁developing ▁app , ▁Pro to . io ▁could ▁then ▁link ▁those ▁pages ▁together ▁with ▁interactive ▁actions ▁that ▁are ▁custom ▁to ▁hand ▁held ▁devices , ▁such ▁as ▁clicks , ▁t aps , ▁tap ▁and ▁holds , ▁and ▁sw ipes . ▁With ▁the ▁platform , ▁users ▁could ▁also ▁create ▁re usable ▁templates ▁into ▁which ▁pre pack aged ▁and ▁edit able ▁elements ▁could ▁be ▁drag ged . ▁Once ▁the ▁user ▁had ▁completed ▁the ▁prototype , ▁Pro to . io ▁could ▁then ▁publish ▁and ▁preview ▁the ▁finished ▁product ▁not ▁only ▁on ▁the ▁web ▁browser ▁but ▁also ▁on ▁the ▁actual ▁mobile ▁device . ▁ ▁Version ▁ 2 ▁ ▁Pro to . io ▁V 2 ▁was ▁released ▁in ▁early ▁ 2 0 1 2 ▁and ▁expanded ▁the ▁supported ▁mobile ▁devices ▁to ▁accommod ate ▁for ▁the ▁Android ▁platform , ▁to ▁include ▁the ▁Android ▁Sm art phone ▁and ▁Table t . ▁The ▁platform ▁also ▁came ▁with ▁a ▁newer ▁user ▁interface . ▁Pro to . io ▁V 2 ▁also ▁added ▁collaboration ▁features ▁like ▁comments ▁and ▁annotations ▁as ▁well ▁as ▁export ▁to ▁HTML ▁functionality . ▁ ▁Version ▁ 3 ▁ ▁On ▁September ▁ 2 8 , ▁ 2 0 1 2 , ▁with ▁the ▁release ▁of ▁version ▁ 3 ▁of ▁the ▁platform , ▁Pro to . io ▁became ▁the ▁first ▁pro tot yp ing ▁tool ▁to ▁allow ▁users ▁to ▁prototype ▁on ▁almost ▁any ▁device ▁with ▁a ▁screen ▁interface , ▁and ▁the ▁first