In my half dozen or so cruises I have found the cruise apps to be well done by the lines I have sailed. There is lots of helpful data to navigate the ship, find food options and so on.
When it came to the casino, however, it really did not interact with the information related to the casino. You instead tracked your slot points on the screen and would have to visit the host desk to check on your table points. With Carnival, you would also use the slot screen to check on your bank balance.
However, on my latest cruise with Carnival Magic, there is a casino tab that provides me with so much more than in the past. Aside from telling me about all of the casino promotions and hours, it now also shows me both my slot and table point earnings, as well as my bank balance.
The app modestly notes that there could be a delay as to how quickly information comes up, but so far I find that when I cash out of a machine and remove my card, ending my session for that machine, my points and bank balance are updated pretty much right away.
This sort of casino tech seems obvious but at many casinos I see delays in how often the information is updated, such as every half hour and so on. Some companies like MGM Rewards seem to be able to maintain near instant updates, but others fall short.
Credit where credit is due, this is a nice enhancement by Carnival that really helps me see how I am doing and what money is available to me at any given time!