Movies by Flixster
Cost: free (Note: Price information for all the apps that made our list is current as of August 2011.)
Devices: available for iPhone, Android, BlackBerry, Windows Phone and WAP
This popular app gives you phone-friendly access to its namesake Web page, a social networking site that enables you to compare movie ratings and tastes with film buffs around the net. In addition to user ratings, Flixster grants you instant access to a flick's freshness rating at aggregator Rotten Tomatoes, which it owns. You can also use it to find movie information, showtimes, maps and ticket prices, or to watch trailers.
A somewhat clunky interface allows you to buy movie tickets through MovieTickets.com, making Flixster well suited either as a one-stop shop for planning a night out or as a habitual hangout for sociable seat-fillers scouting for other affable aficionados.