In all of our visits to Disney we have never been big on 'planning' and never used any type of software. We aren't the type of people who plan every minute with 'walk here at X am then walk there', but perhaps that works for others. Part of the reason we vacation is to unwind and not be held to any rigid schedules. You just never know how crowded a Disney park might be on any given day or how long rides lines will be. Rides can also go down for maintenance/bad weather, so there are only so many things you can reasonably plan for.
If you have small children, trying to hold to some rigid schedule can be frustrating for everyone and you just never know ahead of time what might interest them, particularly if this is your first family trip.
Things like ADR's and park reservations you do need to arrange ahead of time. If you plan to purchase any of the paid Genie options, you can only do those the day of your visit. Other then a map of each park and a general sense of where each of the rides you are interested in are located, I would just let them explore and enjoy their park time.