Walt installed MacKeeper on his Mac. Leo says that he doesn't trust MacKeeper and notes this article on why he should avoid it. Unfortunately, if he tries to uninstall it, he won't be able get rid of all of it. There will still be stuff lingering. This doesn't mean it's malicious, just that it's really badly written.
Walt should search for ZeoBit or MacKeeper and he can delete the rest of them. The "Footy" popup is likely a browser extension. He should drag it out to his desktop and it'll probably disappear.