When you make a connection in Termius, that session is logged in the History section. This provides a log of activity and allows you to easily add these past sessions as hosts.
Tap and hold on a history entry then click the Connect button to reconnect, Save to save as a host, or the red trash can icon to delete it.
Due to restrictions of the iOS platform not all the apps could run in the background.
For Premium users, there is a workaround that makes background work possible.
You can enable location tracking in the app to store the information about the location in your History with the ability to see it on the map. Location tracking will be enabled only when you have active connections just to keep them from disconnecting.