Like on any other view, you can use the left hand menu bar on the top left to switch views and swipe left or right to navigate to the previous or next month. Additionally you can scroll up/down on the lower agenda portion of the view to scroll to previous or subsequent days.
You can also double tap a day number to zoom in to the day view for that day.
To add a new event in your calendar you can do one of the following:
1) Tap on the '+' button at the top right. This will take you to the create event screen for the day you are currently selected.
2) Long tap on one of the day's cells, a 'new' option will pop up, tapping on it will take you to the create event screen for that day.
3) Long tap on the agenda part in the lower pane, you can tap on the day or on one of the existing events, this will bring up a '+' button that you can tap to add an event for that day and time.
Copy and Paste
When you long tap on an event in the lower pane, you'll see an action bar at the top to cut, copy, edit or delete the event. Once you copy or cut the event you can long tap on the upper pane or lower pane to paste your event.
In DigiCal's left hand menu > preferences > calendar views > month > event color, you can choose to use your event's color as the tab color, or as the background color.
As tab color:
As background color:
You can change the app theme to dark theme by going to DigiCal's left hand menu > preferences > general > theme > dark. Then the month view will look like the image below:
Only show 1 day in the lower pane (disable scrolling):
In the preference menu under calendar views > month > events pane > 'Show events for one day', you can disable the scrolling feature of the lower pane.