JustJoin is a helper app intended to simplify the access to Zoom meetings. It is meant to be discreet and be there only when necessary. This is why no icon is shown in the dock.
You can view the app status and access its options through the menu bar. Look for the tiny camera icon with an arrow in it. It should be next to the clock, the Wi-Fi status, the audio volume, etc.
JustJoin is made to find your scheduled Zoom meetings in your calendars. This is how it can display your next meetings in its menu and show a notification when a meeting is about to start.
When you receive an invitation to a meeting, you need to accept it and add it to a calendar that appears in the system Calendar app. Otherwise JustJoin will not be able to know about it.
If you use an online service like Google Calendar to manage your meetings, make sure it is configured to sync with your Mac. You can check this by opening the System Preferences from the Apple menu and choosing Internet Accounts.
In the case you only receive a link to a Zoom meeting and no proper calendar invite to accept, you still can create manually an event at the right time in the Calendar app and paste the meeting link in the event notes.
JustJoin is made to interact with the Zoom Client application. If it is not installed on your Mac, the meeting cannot be joined.
You can download the Zoom Client app from Zoom website: https://zoom.us/download
You must quit JustJoin before being able to move it to the trash.
In the menu bar, look for the JustJoin icon, it is the tiny camera icon with an arrow in it. It should be next to the clock, the Wi-Fi status, the audio volume, etc. Click on it to open the app menu and select Quit JustJoin.
Now you should be able to move JustJoin app where you want to.
If you want to report a bug or request a feature, please use the contact form available in the Feedback section.