Today, Apple unveiled some seriously attractive applications for its mobile devices at the World Wide Developer's Conference in San Francisco. The sad fact for a number of small-time startups is that they directly overlap with their apps and, in many cases, are likely to do the job a little bit better. Here are the app developers that Apple may have put out of business with its new product unveiling today:

Instapaper The primary use of Instapaper is to allow users to save webpages they want to use later. Well now Safari's Read Later feature will be doing just that. Instapaper developer Marco Arment's first reaction on Twitter was: "Shit." But he's looking on the bright side: "At least they're hitting a lot of other apps too. Could be worse," he tweeted. On the upside, Instapaper is still great as an add-on to web browsers like Firefox and Chrome. It's worth mentioning that app reader, Readability will be similarly affected.

Mobile photo apps "Flickr, SmugMug and mobile photo apps like Instagram could be impacted by Photostream, which automatically sends all photos taken on an Apple device to all your other Apple devices, including the Apple TV, and backs them up there for 30 days," writes Liz Gannes at All Things Digital. Other photo apps affected include Camera+ and QuickPix, which will not operate as well as the native Apple apps.

Cloud storage apps "iCloud, Apple’s free solution for storing documents and photographs in the cloud, may eradicate the need for independent services that let users do the same thing," write Sam Grobart and Jenna Wortham at The New York Times. This includes apps such as Dropbox.

Messaging apps iMessage which allows users to engage in group messaging may cut into the businesses of smiliar apps GroupMe and textPlus. However, those apps will likely still do well on non-iOS devices.

BlackBerry Though obviously, much more than an app maker, a number of BlackBerry users continue to cling to the smartphone because of its BlackBerry Messanger app, which allows users to communicate in real time with text messages, photos and video. Now, Apple's iMessage app can do all of that. Looks like that CrackBerry just got a lot less crack-like.

To-do list apps  The Remember the Milk app better watch its back. Apple's new Reminders application serves the exact same purpose of alerting you to things you need to get done.