Apps
Google Play and Apple's App Store have their own rules for real-money betting apps, so bookmakers sometimes offer an Android download from their own site instead. Only install an app linked from the bookmaker's own site or an official app store. Every site in this comparison also works in a phone browser.
Support
Test support before you need it. Send a simple question by live chat or email before your first deposit and see how long the answer takes. If a complaint can't be resolved with the bookmaker, you can take it to the provincial board that licenses it.