PlacePop, maker of a digital loyalty card iPhone app, released a Facebook app this week for monitoring activity in Facebook’s location product Places. It includes a Places activity feed for viewing the recent check-ins by your friends, a feature included in the touch.facebook.com and Facebook for iPhone versions of Places, but currently absent from Facebook’s web interface.

The app also allows users to view a history of friends’ or their own check-ins, Places trending amongst their friends, and graphs of check-ins at specific Places, but doesn’t include the contextual descriptions which users can include with their check-ins.

By using the app, web users and those without a Places-compatible phone can see all the recent check-ins of their friends in one feed, with no need to comb the news feed. Finally, users at home can tell if some friends are at a bar around the corner. Also useful is the ability to see Places profiles of yourself and friends, showing all the check-ins a person has made to date.

The “Trending this week” PlacePop home page sidebar shows the Places you and your friends have checked-in to recently, which often reveal large social events or the workplaces of multiple friends. The Trends tab show simple line graphs of check-ins for popular Place, which can reveal interesting fluctuations such as the increase in check-ins to a public park on sunny days.

Check-ins viewed in PlacePop’s app show the Place, those tagged, subsequent Likes and comments, and a Google map when moused over. Missing are the descriptions users have the option to enter along with their check-ins. This can be awkward, since comments you can see will often refer to the description you can’t see. To see full check-ins with descriptions, users still need to use the mobile Places interface, the news feed, or visit the Place page or friend’s profile.

Facebook could drastically reduce the app’s value by replicating some of its simple functionality, especially the check-in feed. Until then, power users and those without the right mobile phone will get much more out of Places by installing PlacePop’s Facebook app.