Jonas
Jonas is a Reever user/YouTuber who has left video comments on Bree's videos.
From the very beginning, a lot of users thought he was probaly an official character because of the production value and style of editing similar to Bree's and Gemma's videos. Jonas is an orphan and lives a lonely existence alone in what was his parents' house. In a comment to "A Date with P-Monkey, Jonas disclosed that his parents were lost at sea 6 years ago. This kind of unlikely and dramatic detail also points to Jonas being canon (although something like that admittedly could happen). He also says, after talking about his parents, that he can't believe he's telling this to a bunch of complete strangers, which is pretty cheesey, and was probably put in just to justify the unlikelihood that someone would say something so personal on youtube - and to Bree, who everyone knows is an actress. Probably the most damning evidence against Jonas' authenticity is that he doesn't acknowledge that Bree isn't real.
In Bree's Thanksgiving video she acknowledged Jonas: "Well, I feel silly. I thought about what you said, Jonas, and I realized I've been taking Daniel for granted. . . Thank you for reminding me what's important." This reference makes him almost certainly canon. This is similar to the way Gemma was brought into the story. However his comments are still listed in the "comments section" unlike Gemma who is now listed in the official video list.