Path today announced version 2.5 of its iPhone and Android app, the most major release the company has rolled out since Path 2.0 launched in November 2011. Path 2.5 brings a variety of new features to the mobile social networking app, like taggable movies and books, an enhanced camera, customizable Path invites, and redesigned notifications panel. Perhaps most interestingly, version 2.5 adds "nudges," a way to encourage inactive friends to post about whatever they're doing.

If a friend hasn't been using Path for a while, they'll fade to gray in your Path contacts list and a question mark will show up next to them. Tap the question mark, and you can "nudge" them into posting an update or picture. This question mark also shows up next to Path 2.0's trademark ambient updates so you can bug friends to take pictures when they just landed in some other country.

While the new app's nudges sound more like a response to users signing up and then dropping off, Morin makes it seem like the technique could work for any social network. "We've made a creative positive feedback loop," he said, "and it functions in real time. It's like your friend is with you, which leads to a really powerful experience." Twitter encountered issues early on with users joining, then leaving. Perhaps Path is hitting a similar bump in the road, though sign-ups are apparently higher than ever. "We're experiencing unprecedented growth right now," Morin said.

A couple other new additions in Path 2.5 attempt to make asking non-Path users to join in a more refined and appealing way. Now, when you invite friends to use Path, you can customize the email invite to include a cover photo, text note, and audio memo. "We found that Path users are very evangelistic," Morin said, "so we're focusing most on organic user growth and now let you customize an invite."

Many of the features Path added for version 2.5 were inspired by user activity, Morin said. It starts with books and movies — the company found that tons of users were snapping pictures of movie posters and book covers and sharing them with friends. Path continues its quest to curate the best services and apps by partnering with Flixster for movies and Apple for books. So there are now three tabs that let you tag media you're checking out: music, movies, and books. "We wanted to extend beyond music because movies and books can be major personal events during your weekend that you want to share with friends," Morin said.

"We are always searching for design patterns that work better for touch and mobile."

Path chose Flixster because it has a very comprehensive database of movies and actors past and present that now show up in Path as extra context. Additionally, the Path team are big fans of Rotten Tomatoes, which was recently purchased by Flixster and is also integrated in Path 2.5. Path chose iBooks because of its user experience, but acknowledges that Apple doesn't have the largest library of books. "The ISBN catalog is vast," Morin said, "so we'll be rolling out other partners in order to have a full catalog." Path now has pages for books, actors, and movies, where you can see what's most popular — it works just like Path's current music offering. "We want to execute each [partnership] at the highest quality. You should expect that we'll be adding more as time goes on," Morin said.

Lastly, along with adding an updated in-app camera that offers new filters, editing, cropping, and quick video shooting, Path 2.5 adds full-width photos and videos in your feed. "Before, we only used 80 percent of your screen widgth. The extra amount of pixels makes a huge difference," VP of Marketing Nate Johnson said. "We are always searching for design patterns that work better for touch and mobile," Morin said.