Correction — "Know the Area You Have Explored Around the World, Around A Continent, Or Even Around A Country, Where Your Phone Had A Full Battery, GPS Was Available, And There Was Reliable Electricity For Recharging!"
This is dumb. Any given user is going to have massive holes in their map, which, at least according to my experience, will be the best parts of their trips — the parts where they didn't have their phone turned on and didn't care, because it didn't matter.
The problem with all of these dumb travel apps for smartphones is they only seem to be geared toward people who travel with defined itineraries, pay money for accommodation and travel, and only travel in more developed, predictable places. In other words, the most boring kind of travel.
Vayable is the only company I've seen trying to make money from adventurous travel, but even then, it's for purchasing adventurous travel for people who can't find it on their own.
And I still can't find a reasonably good offline maps app for Android, for when access to the Internet isn't so easy.