Jetpack is a great plugin, maybe the best but you would normally need a WordPress.com account to use it.
Fortunately, some of the plugin modules included in Jetpack can be used as standalone plugins like:
- Jetpacks carousel for gallery images - Download Carousel.
- Jetpack contact forms - Download the Contact form.
Hopefully more of Jetpacks modules will work on a standalone basis at some stage.
If you've created lot's of different forms using Jetpacks contact forms but no longer want to install the entire Jetpack plugin and/or connect it to a WordPress.com account you're in luck.
Deactivate and delete Jetpack then install the contact form plugin using the download link above and your short-codes will still work perfectly.
I have installed and tested all these standalone plugins on a demo site and they all work perfectly.
You may also consider installing the Slim Jetpack plugin which doesn't require connection to Jetpacks servers and a WordPress.com account.
Any updates made to any of these plugin modules within Jetpack, by Automattic, will not be available if you are using any of these standalone modules.
You'll need to download the latest version of Jetpack and install the individual module(s) to update the code.