These are the top 5 mobile apps that I've found incredibly useful when it comes to business - and they're available for Windows Mobile.

App #1 - ThumbCal from ThumbApps.com

The standard Calendar and Task manager that comes with Windows Mobile isn't exactly up to much. Poorly laid out, difficult to use - and suffers from being immensely finger un-friendly.

Enter ThumbCal - which is very user friendly calendar and task management app. It strips out all the unnecessary user interface elements which allows the whole process to be streamlined.

App #2 - Sprite Backup

If you aren't backing up your phone, then you're in trouble. How would you get those important business contacts back again if you lost your phone? Back up everything at the touch of a button.

App #3 - ElectroForms Expenses

A finger friendly and easy to use free app to track expenses. Once you've entered your expenses, simply click Send and a nicely formatted Excel spreadsheet will be on its way to your Finance Department just in time to make your paycheck.

Check it out - http://www.mobileelectronicforms.com

If you like that product, the company also provide a custom service to digitize your forms.

App #4 - WorldMate

If you are a Jet-setter, then you need to be in the know with flight times, hotel bookings and so on. WorldMate provides automatic flight and gate information for over 175 airlines around the world. Download it for free.

App #5 - eWallet

There are so many passwords you have to remember between all the different systems or websites that you use - and with a lot of organisations enforcing a strict password policy how can you remember them all?!

eWallet stores all your information in encrypted format so that even if someone were to steal your phone they wouldn't have access to your accounts.