10 Free Add-ons to Extend Google Apps and Make It More Useful

Google Apps (s goog) continues to grow in usefulness over time, especially as you can customize and extend the original platform. You can add a slew of new apps and gadgets to the default selection that appears on your dashboard. The first place to look is in the ever-growing Google Solutions Marketplace which, like Apple’s iTunes App Store (s aapl), is a directory of professional apps and services.

Besides the Solutions Marketplace, there are other ways to extend Google Apps. For example, you can add just about any app from the Google App Engine, which includes its own development platform. Also worth mentioning is the fact that you can also addi apps and gadgets from Google Labs. There are only three you can add to Google Apps at this time, but they are excellent ones: Google Moderator, Google Code and Google Shortlinks. There’s no doubt that there will be plenty more to come.

Here are some of the best free add-ons that I’ve found for the  Google Apps platform.

Google Contacts App for Google Apps. Google has a standalone Contacts app (currently in beta) for the Google Apps platform. Using this app, every member of an organization hosted on Google Apps can share a centralized address book. You can add it to your dashboard by clicking the “Add more services” link.

Zoho Project App for Google Apps. Just because Google Apps doesn’t have a built-in project app doesn’t mean you can’t use one . You can add Zoho Project, which provides a free basic plan for one project.

Zoho CRM allows you to add a Salesforce-like CRM app to your dashboard. The free version lets up to three people from your organization share customer and sales information.

Tungle works well with Gmail and Google Calendar and makes scheduling meetings much easier by allowing people from different companies to see available times (see our previous review here).

Google Contact Importer lets you import contacts from Microsoft Exchange (s msft) to Google Apps. It’s free for a single user, or there’s a premium version for multiple users or everyone on the entire Google Apps domain.

Yuuguu is a free screen sharing and web conferencing service that works with GTalk and Gmail (WWD review here). There are plans to release a paid corporate edition down the road but for now it’s totally free.

Gantt Charts for Google Apps adds the ability to create Gantt charts to your Google Spreadsheets.

Google Short Links is a URL shortening service for Google Apps and allows you to use much shorter more descriptive names for URLs.

Google Docs Backup does just that, backs up all of the documents stored in your Google Docs area within Google Apps. It’s free for a single mailbox user. There’s also a plan available that will back up Docs for all for all users on a domain.

PDFescape provides a free online PDF reader, editor, form filler and form designer.

What add-ons have you customized your Google Apps with?