keep on top
keep on top (of someone or something)
to stay well-informed about the status of someone or something. I need to keep on top of the president, because I am doing a report on him. News is easy to get these days, and I do what I can to keep on top.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.