Have you ever sent a text, searched the web, or updated your Facebook status via smartphone or tablet while watching television? If you have, you have joined the majority of Americans.

The ‘second screen’ phenomenon is growing at a rapid rate. A recent study from Yahoo found that 86% of mobile internet users aged 13-64 have used their device while watching TV. Over 50% admitted to texting, while over 30% have used mobile apps, browsed the internet, and visited Facebook or Twitter. While this trend continues to grow, how can marketers take advantage of this activity?

One option many Super Bowl advertisers chose this year is mobile app integration. Brands including Pepsi and Toyota partnered with mobile app Shazam, which is able to identify music or a television program from the audio it senses. Viewers were to open and activate the Shazam app during the commercial and, once the ad was identified by the app, were served a custom offer or content. Shazam reported that it received 'millions of tags' during the game, but were users really engaged with their mobile devices during the biggest sporting event of the year? Mobile firm Flurry says ‘Yes’.

A study conducted by the company found that app sessions were not started during engaging moments such as big plays and the halftime performance, but app use spiked at off-peak times such as after commercial breaks and during the 3rd quarter. The study also found that apps were hugely popular overall during the big game, with 98 million people accessing apps during the same time period 111 million people were watching the game.

Shazam is currently the big name in TV check-in apps, but let's review some of the up-and-coming contenders in the market.

Getglue allows users to check in to TV, music, and movies, and can also serve discounts and sticker rewards. The app is available on all major mobile devices, reached the 2 million user mark in January, and is evolving to become a recommendation platform which will "not only connect users to content across entertainment spectrum via their previous actions, but one that will also fully integrate brands in an organic way".

Miso is a social TV platform on which users can currently check-in to TV episodes and movies to share what they watch with their social network, discover what friends are watching, and create lists of favorite shows and movies. The app is expanding to include marketing opportunities in which users could check in to Gossip Girl and buy a dress featured in the episode, or purchase a song which was featured in the latest episode of Mad Men.

As the popularity of the "second screen" continues to grow, so will the use of apps which can integrate the experience between the screens. Have an opinion on TV check-in apps? Leave your thoughts in a comment below.