1. Twitter App. The Canvas Twitter App is easy to install, and it can display any Twitter user or hashtag, but it is really limited. Unlike a real Twitter widget, it does not display any media — no images, no video: sample page with Twitter App.
Depending on how you use Twitter, this might not be a drawback, but my main interest in using Twitter is sharing graphics, infographics, and videos, so for me, the Canvas Twitter App is a dud. This is also a dud if you want to display the results of a Twitter list, and lists are one of the most powerful ways to use Twitter.
2. Twitter Widget. Twitter widgets, on the other hand, have great media player features, both for images and videos, along with other content-specific displays; Storify slideshows, for example, work great in Twitter.
It's easy to make a Twitter widget: just go to your account settings, choose widgets, and then configure the widget based on a huge range of choices: user, hashtag, lists, etc.
The problem, though, is that you cannot just paste the widget into Canvas as you normally would be able to do (argh!)... but there is a nifty hack you can use which I learned about at the Canvas Community.
What you need to do is get the widget ID from the Twitter widget page (it's a LONG number), and then use the code below. Paste in the long number, put in your Twitter handle, and decide how tall you want the widget window to be. Then, paste the result into the HTML view of a Canvas page, and you are good to go!
Here's a screenshot of the OUMindsetPlay Twitter widget on my course wiki's homepage at CanvasMythFolklore.net. You can also see that same widget displayed in the sidebar of this blog too!