Quora has answers of all your questions but there are many formalities that we have to do.i don't like to enter or download apps for doing work for 5 min. .even though they donot open their answers if you donot complete the formalities which is one of the worst thing.and yeah I remember some science answers were also incorrect.but there answer are quiet good and quiet understandable.but I will say they should know that people don't like to download special app they have several options or many more sites for a single answer