If you are getting notifications from FlashcardAnalytics, then your Mac is infected with adware. FlashcardAnalytics is adware for Mac.
FlashcardAnalytics changes setting in your Mac. First, FlashcardAnalytics installs a browser extension in your browser. Then, after FlashcardAnalytics hijacks your browser, it modifies settings in the browser. For example, it changes the default home page, modifies search results, and displays unwanted pop-ups in your browser.