To get information about the boat you can go to the website for the company that handles the boat which is called “waxholmsbolaget”. This website has pretty much all the information you need about the boat. The website has its own travelling planer which I think needs improvement, because when I tried to make a travel search the box where you should put in the information about where you are travelling from didn’t have any alternatives to choose between which the box for the destination has. Besides that, I think this is a good page for information about the boat. It contains everything from information about the boat's history to the current time tables.
Since the boat is included in the “SL travelling system” you can get information about the departures and arrivals on the SL website. This website can give you information how to travel from point A to point B anywhere within Stockholm county.
Both these websites have their own apps. I haven’t tried the waxholmsbolaget app yet but the SL app I am very familiar with. For most part it works fine but in some special cases it can give another travelling way other than the optimal (which most people are looking for) or give too short time between stops so that you miss the next bus or train because the previous was late.
When we went to the boat to do the interviews, there were information booths before the entrance where you could ask questions about buying tickets or similar. I think this is mostly for tourists, because “Gamla Stan” is a very popular place for tourists and some may walk around there, accidentally walk past the wharf and find themselves wanting to go on the boat. Thus it is good for them to find information at the spot.