They can appear quite cryptic, so hopefully these explanations will make sense and allow you to configure the app for your particular needs. One thing worth pointing out on that subject is that there is no one "perfect configuration"; every single scene is different, so you have to experiment with each setting to find the right balance for you.
All the settings can be found in the app under Settings > Advanced:
Detections For Trigger
This number represents the number of frames in a row that must contain motion in order for a motion trigger to be fired, and therefore perform a capture. So if you want to detect motion that is more pronounced, set this to a higher value so you can be sure some genuine and interesting motion occurred. For example, if you set this to 10 then each of 10 successive frames from the camera input must contain motion in order for a picture (or video) to be taken.
Processing Scale
Each frame from the camera contains lots of pixels to process, so it is wise to scale this down in order to speed up processing. So lowering this value makes the frame to be processed more pixelated (you can see this on the Mini-Preview within the app as the camera is running) and thus means less processing time/power. It also means the frame contains less information so you risk missing the more subtle motions in the scene (although this of course might be a good thing for your needs). So if you want to process faster and become less accurate, set this to a lower value.
Sensitivity
How sensitive to motion the app is. Can't say more than that really!
Frame Delay
The gap between the frames that actually get processed. So rather than processing every available frame, only process the available frame every certain amount of milliseconds. Similar to Processing Scale, this means less processing time/power needed to run the app. Of course it also means that you can catch more prolonged motion to cause a trigger. For example, you could set this to be 1000ms and Detections For Trigger to be 10 which would mean only motion that has occurred for roughly 10 seconds (10 x 1000ms) would take a photo (or video).
Gaussian
This smooths out the current frame to be processed in order to reduce noise in the picture. It means slightly more processing time/power is required though, which is the trade off for using this setting.
So combine these settings to match the needs of your scene. However, there is no combination of settings that I know of that can ignore the motion of trees - the app can't distinguish between what type of object is actually moving, so there is no "Ignore Trees" setting I am afraid... all you can do is try adjusting these settings to try and lessen the amount of times moving trees to cause a trigger. A moving tree is motion after all!
