Personalized magazine app Flipboard has finally come to the Apple iPhone after enjoying success on the company's other mobile platform, the iPad. Flipboard is a free download from the App Store, but within the first day of launching the service on the iPhone, the company admitted that high demand had crashed its servers.

Due to high demand, our service is currently down, Flipboard tweeted. We are working to resolve the issue as soon as possible. Thank you for your patience.

Flipboard aggregates content from publications, blogs, and social networks, including Facebook, Tumblr and Instagram, to create a completely personalized magazine experience that learns your preferences over time and tailors its content to your interests. Flipboard was named Apple's iPad App of the year in 2010 and one of TIME's Top 50 innovations.

Current owners of the iPad app have no need to worry: By downloading the application and signing into their free Flipboard account, those owners will see their personal account information and preferences automatically sync onto the new application.

The key difference between Flipboard's iPhone app and its iPad app, besides being smaller to fit the 3.5-inch screens on the iPhone and iPod Touch, is a new feature called Cover Stories. The new feature offers a selection of interesting articles and photos being shared with you, via social media or otherwise, in real-time. Flipboard says the feature is coming soon to the iPad.

In addition, Flipboard for iPhone is a speed demon, making flicking through articles and across verticals at any pace both extremely realistic and satisfying. The only negative of the iPhone app is that it can only show one article at a time on the screen, and swiping through articles is done vertically instead of horizontally, as on the iPad.

Flipboard has raised $60.5 million in funding, but is facing unprecedented competition from other personalized magazines from AOL (Editions), Yahoo (Livestand) and Zite.