Group planning: Free mobile apps and online tools

Good for: Social-media–addicted vacationers
How it works: We’ve all fallen victim to the flurry of round-robin messages that inevitably occurs when trying to arrange a group getaway. This application allows friends to eliminate the overload by creating a trip, adding travel buddies, booking hotels and divvying up the cost among invitees, all within Facebook. Each trip gets its own page, with separate tabs for organizing the basic details (dates, times, locations), accommodations and car reservations, plus group discussion threads and photos.
Where it’s available: Facebook

Good for: Overbooked nine-to-fivers
How it works: Nailing down a day and time for a large-scale meeting can feel like an impossible game of Tetris—no matter how you rotate the pieces, nothing seems to line up correctly. To remedy the problem, this Web-based tool lets professionals suggest up to five different meeting times, which attendees then respond to by clicking best, yes or no. Once TimeBridge finds the optimal block, it automatically reminds participants to convene at the specified time and location via e-mail or SMS message. Head honchos can also create an agenda and note follow-up items for each gathering to ensure efficiency.
Where it’s available: timebridge.com

Good for: The designated “cruise director”
How it works: It’s easy to talk about making plans with friends; actually getting everyone together in one place at the same time, however, is a lot trickier. Pulling location and venue information from Foursquare, this scheduling app prompts users to create “hangouts” by choosing guests (you’ll need to link your account to Facebook) and setting a date, hour and location. Your pals can weigh in with their opinions and preferences, and if arrangements needs to be hashed out via chat, you can do so within each event, too.
Where it’s available: Mac App Store and chillwith.me

Good for: Indecisive friends and the mathematically challenged
How it works: Set to launch on Oct 24, this service curates outings for circles of four to six people. Once you choose your activity (whether it’s a girly bonanza, a local brewery mixer or a pasta-making class), you’ll be prompted to invite buddies, who then sign up with their payment details to reserve a spot. You can communicate with the participants via Facebook or Twitter, but the program also automatically creates a circle within the companion Facebook and Android app GroupMe, so that friends can discuss any last minutiae before the event.
Where it’s available: experiences.groupme.com. TONY readers get early access through groupme.com/tony.