Kourtney Kardashian stopped by a friend's house in West Hollywood on Monday, and the reality starlet looked amazing in a leather jacket, black leggings and a cropped top. We love that she's flaunting her abs in the middle of December!

In other news, Kourt finally relaunched her blog this week -- and debuted her new app, which is simply called Kourt. Sisters Kim, Khloe, Kendall and Kylie's apps were released in September, but it sounds like Kourtney's will be very different from everyone else's. "I cannot wait to share my life with you," she said in a video message to fans, adding that she'll be sharing "original posts on topics including personal recipes, influencer Q&A's, healthy living tips, home design ideas, shopping and beauty guides and kid-centric obsessions." Is she trying to be the new Gwyneth?

"I am so happy to finally have a space where I can share my obsessions and the things that I am most passionate about," she said in a press release. We're curious to see whose app is the most successful ... you know the ladies are totally competing with one another!