How can a number of watchers and digest cycle time affect the performance of the application?

The working of digest cycle involves going to each and every watcher and informing it about the model change. This task will consume more time if the number of watchers will increase. Angular team has recommended implementing not more than 2000 watchers per page. To check the performance implications of digest cycle, we can use online tools like Batarang. These tools are mere extensions of google chrome & show the time taken by each digest cycle on a single page.