Android: Last Message is a simple, yet necessary (for some) App that automatically detects your phone levels and informs your friends and contacts via texts, e-mails, Facebook posts and Tweets that your battery is going dead and you'll go offline for a while until you find some juice for it.
When looking at present technology and how it's involved in the last 20 years or so, we get an indication get an indication of where we'll be a year or so by now. As to where we'll be a decade from now you wouldn't believe! This is guaranteed to your mind!