For example:
- take a ND110 - 10 stop filter.

First take a shutter reading in the camera using aperture mode without the filter. Take the shutter speed and select it in the application on the top left drop down menu and then select your filter on the right drop down menu.
Compose your photo before placing the filter on the lens. Anything over 30sec shutter setting on the camera which is the longest a camera will allow before you having to switch to bulb mode and the timer will automatically appear in the application with a go button.

Once the camera is set up with the filter on, press the shutter release button and timer go button(if present) on the app at the same time.

Not in all cases, the timer will appear. Only if you need to use the shutter over 30 seconds.

Don't forget to use a cable release button to prevent movement of the camera during the exposure and ensure a crisp sharp photo.

To abort the timer simply press abort on the left and then confirm on the right (new addition since version 1.1 due to accidental cancelling of the timer)

To use the timer again after a shot, simply hit go again (new addition since version 1.1 due to crashing).

Good luck!!!

Update Description:
v1.2:
- Bugs have been removed in this version but please let me know if you encounter any.