What is Wordpress Jetpack?

Wordpress Jetpack is a set of Plugins by Wordpress.com for Self-Hosted Wordpress Blogs to introduce several features that are previously available for Wordpress.com's Users

As stated earlier , it's a set of plugins which will introduce some features on your Self-Hosted Wordpress Blog, but according to our Users it's much more than that and posses the ability to get most coolest features of  Wordpress.com to Self-Hosted Wordpress Blogs

What Plugins/Features are Included in Wordpress Jetpack?

WordPress.com real-time stats : this will provide you with simple ,concise and time saving stats with no advance Data or confusing logs. This plugin will add a Smiley at bottom of your Website and "No. of times it's been loaded " are counted

Shortlinks : Will add an option to short the URL's of Every Page and Post by generating a Wp.me shortlinks

Sharedaddy : This plugin will add Social Sharing Buttons on your Websites Post and Pages . it includes Facebook ,Twitter , Reddit and many more...

LaTex : will markup your post for Complex Mathematical Equation with LaTex Markup Languages

Shortcode Embed : will provide option to easily embed content from Youtube, Vimeo and Slideshare

Wickett Twitter Widget : It will add a Sidebar Widget to show your Recent Tweets on your Blog.

Spell and Grammar Checker : This is previously provided by the popular Plugin "After the Deadline" it will check your post for Grammatical and Spelling Errors, and will result in more efficient and improved Content.

Gravatar Hovercard : Show a Tooltip pop-up business card of your user gravatar profiles in comments, it is more efficient in giving your blog a dynamic Look

The Problem with Jetpack : The biggest Problem Wordpress User face is that  the theme is   not compatible with the Jetpack .  Most of the Theme Developer , create a theme by keeping Wordpress Jetpack [due to it's popularity] in mind, If your theme is not compatible with Jetpack , you should contact the author/developer or else read the guides to fix it up.

we'd personally tested it with BuddyPress Default Theme, Thematic,Hybrid and Thesis Framework.

Greatest advantage of this plugin is  that this is approved and from the most trustworthy Source i.e.   Wordpress.com  and regularly updated to fix bugs and introduce more features