Just to help out I'll run through what I've found so far....
First run the app is blank, get yourself to a station try to run the game Borderless windowed so you can alt/tab to the desktop.
In the app in systems and stations part, right click and add station, fill in the details. This gives you a blank commodity page for that station.
What I now do is click on that station in the left panel which will give you a page in the middle with all the commodities shown.
Click at the bottom "Data entry mode" This new panel pop up should be in focus all the time. ie on top of the game.
Get the stations page open with commodities...
Start at the top... say maybe Hydrogen is top, on the app pop up right click Hydrogen and set the supply state high low or medium on either supply or demand.
Move down setting any/all commodities you are interested in (I just do them all)
Do this for every station you stop at, the other bit at bottom right is self explanatory once you start using it.
Now ..this is a good bit..
If you get a mission where it says "get me 7 Consumer Tech" (as an example) Use the drop down at the bottom to set Consumer tech in there and click need, it will show you (from the stations you have entered) where you can get said item.
Just a quick run through of how it works, I love this little app as all it is doing is replacing the pen and paper with a data entry system with storage and retrieval...