I found that the thing missing most to me while playing Fallout Shelter is the lack of inventory management. Sure you can look at unequipped items but say I gave a girl a piece of clothing and wanted it for someone else, but she's now pregnant, I'm stuck clicking everyone until I find who's wearing what I'm searching for. Same goes for guns, when not in use people stow away their weapons making it so you have to tap on people again until you find what you want. This makes things like arming your vault really annoying because if you want a specific gun for a newly designated explorer, fore example, you have to dig around for that specific gun again. It becomes much easier to just not have anyone holding onto any weapons until something pops up, leaving them unarmed at the beginning of a fight. What I'm proposing is a new menu with all your dwellers, each with their equipped clothes and weapons next to them where you can easily switch out their clothes/weapons from that inventory management menu
For an idea of how the community feels here's my Reddit post about it with 89% of people upvoting it at the time of this post:
http://www.reddit.com/r/foshelter/comments/3a6g0p/how_do_you_keep_track_of_what_people_are/