That's a tall order for $400 bucks. I know since I recently shopped.
If you have to have Navionics the Garmin is out. This is from the Garmin site: "However, we must inform users that, in December 2014, Garmin announced a change to their software thus making their devices incompatible with Navionics charts. Customers that utilize software version 2015.0202 or newer will no longer be able to use Navionics charts."
I think the Lawrence HDS-7 Gen2 Touch can do everything on your list but that is over $700. It appears that the apps and phone/tablet capability is the most difficult capability at a lower price point.
I'm not real familiar with Humminbird's app capability, but I think it is only offered on the ION series which is very expensive.
Raymarine has app viewing in their Dragonfly series but I don't know the full details, you may want to check it out.
I hope this helps a little and saves you some time.