Last Message has a digital bandaid. Keeping track of how much juice is left on your Android device (sorry iPhone users), Last Message will ping any contact you choose automatically. This free app runs behind the scenes, monitoring battery power, and then alerting contacts of your choosing via Twitter, email, text or even Facebook if your power dips below a certain percentage. Messages can be customized, as well as your contact list. So if you don’t respond to that one client we all have, who wants to know you’re available when they are—now they’ll know why.