We recently supported Safari, but you might encounter weird bugs when screensharing. You can choose the "Let Me In Anyway" button to access Here on Safari.
Our iPhone app is now in the Apple AppStore. Head to the AppStore and search Here - Talk, Text, Watch OR head to this link to download our app. You can check out all of our tips and troubleshooting guides for the mobile app in our "Here for iOS" section of this FAQ.