Please reconsider Customized Item Properties
I see you've already declined this, but I'd really like to urge reconsideration. Seems to me the biggest advantage of an app over just a set of static, paper lists is the ability to use logic based on weather and destination data to modify the list. Suppose, for example, users could set a condition for "Bathing Suit" to appear on packing lists only when the forecast calls for temperatures over - say - 70 degrees? Since you say you ARE considering another excellent suggestion to invert the data structure - starting with items rather than activities and allowing those items to be assigned to multiple activities - then isn't this request just an extension of the same thing? Using items as the basic unit of information and giving them properties? If you start with - say - "Sunglasses" and let the user give that item the property of appearing in both the "Beach" activity and the "Skiing" activity... then couldn't it have other properties as well? It would certainly be more helpful than a paper list if I could set "Snorkeling Gear" to be included when I'm going to the Bahamas in 80 degree weather, but excluded when going to Omaha in -20 degree weather.
I agree with the idea of items being suggested only when they are relevant, especially based on weather. PackPoint does this for some items currently. I'd like to clarify a point where I'm confused on this idea submission - shouldn't beach gear be suggested regardless of whether if you tell PackPoint that you are going to the beach during your trip? Or to use your scuba gear example for the Bahamas, PackPoint would only tell you to bring scuba gear if you create an activity for scuba, then choose it for your Omaha trip during the winter (which of course wouldn't happen).
So I'm not quite sure on the problem to solve? Maybe I'm not thinking of the use case properly.