Timing is everything in a job search, and these five apps bring the latest opportunities to your virtual door. Featuring some of the largest online job sites, the apps let you search and network from wherever you are. All are free and support iPhone and Android.

Network On The Go With LinkedIn

LinkedIn is a professional networking essential, and now you can always be in the know. Just like the site, the app lets you search for jobs, look up companies and individuals, and make and receive updates. You can learn about people right before an event or connect after an introduction. You can travel light and still receive the latest updates, send someone a quick note, or arrange an impromptu meeting from your phone.

As a business app, LinkedIn supports iPhone, Android, BlackBerry and Palm Pre.

Take Monster With You

Monster.com set the job site standard years ago, and its Monster Job Search app delivers the same features to wherever you are. As long as you have a Monster account, you can find and apply for jobs from your smartphone. If you use your phone’s GPS, the app will flag local opportunities. You can set alerts to receive job notices that fit your criteria, such as title or length of position, so that you can act as soon as a new opening is posted. The resumes and cover letters saved to your Monster account give you everything you need to apply for positions on the go.

Go Global With Job Search by Indeed Jobs

If you are open to global opportunities, then the Indeed app is for you. This offering from another of the big sites lists openings not only in the U.S. but also in Canada, the UK, Australia, India and more. You can set alerts to receive notifications about internships in Sydney or finance positions in Singapore. In your app search travels, you just might find your dream job.

Browse Jobs by Careerbuilder.com

More people visit Careerbuilder.com than almost any other job site, in part for its unique listings and information on a range of work-related topics. The app brings you all of the site’s features wherever you are. A smart job search tactic is to monitor several sites, and Careerbuilder is a good one to include in your mobile list.

You Want Uncle Sam’s Official Job App

USAjobs.gov is the official site for U.S. Government jobs, and its vast database now comes in a Government Jobs app. You can search using criteria such as city and job function and save your results for easy access. Like other apps, Government Jobs lets you set alerts so that you’re the first to know when the right opportunity comes along.

Image Credit: Some rights reserved by William Hook

Chris Keenan is a blogger for Get Interviews, an online website dedicated to teaching job seekers how to write a resume.