Just use common sense
I have been using this app ever since I came to Chicago 3 years ago and its the only one I have ever liked. Its easy to use and if you use some common sense you wont miss your bus. This app and most tracking apps get their data directly from the cta trackers in the buses or trains. So when it says they are 5 minutes away thats an estimate. Depending on traffic it could speed up or slow down therefore arrive before the estimate. The buses that dont show on the tracker just dont have their tracker on, aka a ghost bus again not the apps fault. Its only as good as the cta system allows it to be. So dont let the other reviews persuade you not too use this.
Late joe about
Transit Stop: CTA Tracker., v7.7.9