Basics
There are 4 main modes: 2 for phone, 2 for tablet/ desktop
Phone vertical
Phone horizontal
Desktop vertical - requires keyboard
Desktop horizontal - requires keyboard
To switch between modes:
Switch between horizontal and vertical: Enable Auto Rotate in device configuration, Set the device orientation (place the device in landscape or portrait position) then launch the app
To switch between desktop/phone mode: Open View menu > Change mode> Select desired mode and restart the app
By default app checks if device screen width is greater than screen height, then (if it is greater than 130 mm) it enables desktop mode, you can force app to open in desired mode tho.
When minimized app enters PictureInPicture mode and stops rendering and processing data, depending on android behavior 'if a threaded task is running' either thread is paused or not. But this mode speeds up, overall performance.
You can use mouse and keyboard: see keyboard shortcuts and mouse gestures
To open context menu without mouse you need to long tap and then release. Long tap equals to tap that you hold longer than 300 ms (approx 0.3 sec) but do not hold too long (1.7 sec or more) cause it will discard the tap
REM button doesn't delete selection when in LIN mode.
Navigation in 3D mode (desktop mode):
Press W, S, A, D to move camera around, holding mouse or tapping on the screen will rotate the camera, when holding Alt you will move left/right and up/down depending on the mouse movement.
Navigation in 2D mode (desktop mode):
Press C - cam mode
Press Q - translate/rotate/size/scale mode
Press S - select mode
Press I - insert mode
Press X - lin mode
See subsection of basics to find out how to navigate and use the app