this is an app that can explain a photograph or picture by create mark points on it.
to create a mark point ,u can just simply touch where u want to show sth on ur screen a while ,then u can explode the tools icon ,by select the different tool ,ur can make an annotate by text,voice or simple hand-sketch. after the annotate is saved in this mark point. u can share the picture with these mark points by WeChat, i-message or email to the people who have this app .