Seems I recall a post in the forums not long ago asking for a native Craigslist search app and lo and behold, a new app from Soluteo offers just that. Classified Search brings easy Craigslist access to BlackBerry 10 with a simple, yet native experience.
The app has all the basic things you'd expect. Upon launch it asks the location you want to search in and you're free to look for whatever from there. It also keeps track of your history and you can star favorites for if you ever need to refer back to an ad.
Best of all, Classified Search is available as a free download so if you give it a go and it's not for you're out nothing. If you love it, then you got a great app for free. Can't really beat that. Classified Search has support for all available BlackBerry 10 devices according to the BlackBerry World listing so give it a go.