And then there are the applications that come out of the blue and make life easier. A few years ago, LogMeIn(LOGM)came out with the Joinme web conferencing service which ran circles around bigger, established rivals like Cisco (CSCO) Webex and Citrix(CTRX) GotoMeeting.

Basically, whoever hosted the meeting shared a web link, the guest clicked on it and they were off to the races. No download. Each. And. Every. Time.

Hallelujah.

That’s a long way of saying that a new mobile address book by a company founded by LogMeIn co-founder Marton Anka might be worth a look. Caret, a free app for iOS (AAPL) and Android, was announced this week.

The company has done interesting things to take advantage of modern smartphone capabilities.For example, if you put your phone face down, you will show up to your friends-and-family as unavailable. If you (well, your phone) is moving faster than 10 mph, Caret will indicate to others that you, likely driving, can’t respond to texts or calls right away.

Since many people already use their phones to organize their lives, enhancing key features like address books makes sense.

In a statement, Anka, CEO of the San Francisco company, said:

We created Caret on the simple premise that as smart as our phones have become, our address books are still very basic. People are engaged with their friends and colleagues via their mobile devices and Caret is taking advantage of both our desire to share and the smartphone’s smarts to make that sharing intuitive, useful and exceptionally easy.

For more on mobile apps and their impact on our lives, see the video.

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