The bus tracking app i like to use for my Android phone is called "Transit Now Toronto", which can be downloaded from Google Play store if you own an Android Phone. This app allows you to add a particular bus route as favorite and every time you open the app and click on the favorite icon, it gives you the arrival times of the bus routes you chose as favorites earlier.
You can also click on the "Nearby bus" icon which tells you the arrival times of all the buses coming to your road intersection, where you are standing on. The best of all is the "Map" feature where you choose a specific bus route and then click on the "Map" icon which displays the exact location and direction of the buses in real time live. This map display of buses location is more accurate than simply arrival time feature because sometimes the apps show a bus is coming when actually the bus is not coming and is still very far away.
This app also allows you to access the bus arrival times from your phone's lock screen or status bar. You can also set an alarm to alert you when the bus is about to arrive at your location. There is also the TTC alert feature which tells you if there are any alerts such as route diversions for bus, subway down, or station elevator out of service. Another cool feature is the station info which tells you the first subway train and last subway train info for the subway station that you choose. A subway map is provided for anyone who wants to know which subway station there are traveling to and from.