The SF mobile app is available for download from the resources page. The app is free for all members. It will allow you to get notifications on your mobile device whenever a thread or forum you watch has a new post, when your thread or posts get replies, when you receive a private message, etc. Chat is not accessible on the app as it conflicts with the software on the site.
The links to download are in the resources area - https://www.suicideforum.com/community/resources/categories/example-category.1/