We already covered eBuddy Mobile, but that's simply a version of the site that works on tiny mobile screens. Now there's a java app for mobile phones, aiming to serve at least of fraction of the site's 10.3 million monthly unique visitors. The app is in private beta and will be released in a few weeks time.
Building an app is obviously a pain - it needs to work across hundreds of handsets, and early mobile successes like Twitter suggest that users don't really care for downloads anyway. Text messaging, meanwhile, works on all handsets: it's the obvious way to transition these services to mobile.
The only benefit of a java app: maybe they can get it pre-installed on handsets through deals with the networks. If I remember correctly, eBuddy also has a stronger European presence than rival Meebo: perhaps Europe's head start in the mobile space will put them at an advantage.