Wikipedia is the best app understand the information which we didn’t know and can ask the meaning of anything and get the answers it is the best app to learn and they give the day special which means it give the information occur in different years of that date and also give the article whish you can read and understand that and you can ask anything and the answers given from it is marbalous I also tried it and stell I using this app and gaining my knowledge I recommended you to use this app and get benifit from it try it ones you recommended other also