You can view all candidates who have set themselves as available through the App (real time availability by clicking on 'Available Now' on the Dashboard) by following the steps below -
Scheduling >> Availability
In addition, if the 'Available Now email notification' is ON from Settings >> Settings >> General, the candidate owners will receive email notification when candidates set themselves available (only the 'Available Now' option - not to be confused with general availability).
Note: To avoid spamming recruiters, the email will be triggered only once in a 12 hrs window for a specific candidate even if they pressed it multiple times.