Unfortunately the app is not very accurate. There have been times when I have seen a ride with a 20 minute wait in the app when it's really over an hour. The wait times at the ride entrances are not always accurate either.
Some rides open later than the rest of the park. Ice Breaker and Mako open late, possibly Kraken as well. If would try to ride Ice Breaker earlier as well as the capacity isn't the greatest and with it having a lower height requirement, it also can get a long line.
I would pay attention to the show times and try to avoid rides nearby when the shows are set to end. That means avoiding Ice Breaker when Orca Encounter lets out, avoiding Journey to Atlantis and Kraken when the dolphin show lets out. Mako when the Sea Lion show lets out.
Manta typically opens first, if you are in the front of the crowds, I would ride that first or else save it for later in the day as almost everyone goes there first. If you care about the water rides, either ride those early or late. Both Journey To Atlantis and Infinity Falls can get over an hour wait on a crowded day during the summer especially if Journey To Atlantis is still not using the unloading station reducing capacity.