As park veterans, we don't use any assistive devices. We would like to use wait time apps, but don't have the right smart phones, as it's really expensive to use Canadian ones @ WDW. We used a guidebook and Passporter for our 1st trip together after we married (WDW & Cruise), and never again.
Based on what I read on these boards, the touring patterns seem to be off. It's funny to me how people pay money to have someone give them an idea of crowds. This info is based on old crowd patterns, which can, and do change. As an example, we've been coming for 2 weeks each July for 10 years, and have stayed at every resort (except GF) as we are DVC members, and have never seen a July, especially 4th, with these low crowds.
Have talked to tons of CMs and other DVC members, and we are thrilled at the low crowds - less tour groups here as well. Also, lots of walk-ups at restaurants - they aren't as busy either.
Conversely, after 15 trips, I had never seen crowds like what we experienced in March. Our last March was busy, but nothing was like the week of St. Patrick's Day this year. Busiest I have ever seen it - busier than Christmas/NYE and July 4th!!! It was insane!!!
So, in answer to your question, we are our best judge of crowds. If it's too busy, we adjust our schedule, and park hop. If one side of park is crowded, we switch to other side. We hardly wait in any lines at all, as we've BTDT, and so we adjust ourselves according to what we are experiencing in the parks at that time.
Tiger