There are probably (tens of?) thousands of restaurants in Canada that take Amex. The list would be unwieldy and rather pointless.

If you really want to know whether a restaurant takes Amex, use Google. For example "Restaurant Toronto Bay Street American Express"

I don't know what card you have or how you use your App, but I have a 'My Platinum' feature on the app which has, among others, a 'Dining' section which lists restaurants near me that take Amex. I can enter a city, country, map, etc.