It’s no secret that Craigslist’s user experience sucks. Yet no startup has been able to unseat the local listings giant because it has the thing sellers care about the most: liquidity. That hasn’t stopped the recent spate of sites like HipSwap, Zaarly and Krrb, as well as mobile apps like Bondsy (yet to launch) and the week-old Yardsale, all of which offer improvements on Craigslist’s crappy UX with their own twist on local listings.

Add one more app to the mix: This week New York-based Ketup launched its iPhone app for Instagram-style local listings.

The app works similar to Instagram in that, upon opening it, you can see images of listings based on location and sortable by category. Below each listing is a messaging field for contacting the seller. The company was created and self-funded by Troy Osinoff, and Conway Anderson, formerly of Meebo and Pandora.

With so many new players, it will be difficult for any one to get wide enough adoption to provide that sweet liquidity necessary for a marketplace to thrive. But many of the new guys, including Ketup, rely on social media to push its items out to their connections on Facebook, Twitter, Instagram, or Pinterest, which should drive sales.

The social tie-in does more than just provide promotion, it’s also there for security and vouching. Ketup requires a Facebook login, which its founders believe help cut down on fraud. Likewise, buyers can see when they have a second-degree connection to sellers, providing a degree of verification.

As the Web makes its shift to mobile, Craigslist loyalists may actually shift over to these new options based on ease of use. How much easier is it to snap a photo of something on your phone and instantly list it, rather than upload the photo to your computer, then upload it from there to Craigslist, then write in the description and post it?

Bondsy, for example, doesn’t believe it will compete with Craigslist or eBay at all, because it aims to recruit users who’ve never used a marketplace site before.

Ketup’s differentiator is that it focuses on vintage, handmade, and antique items, but locally. The app features a follow button so fans of a certain designer or seller can see new items. It will appeal to local sellers of large flea-market type items that don’t appear on Etsy because they’re impossible to ship. The company would be happy to integrate with Etsy but hasn’t gotten to those talks yet, Osinoff says.