When I setup a new phone with the Windows Phone operating system (previously called Windows Mobile), I tend to install the following applications and utilities first. I use them all on a regular basis, and they are FREE!
Total Commander is a top-notch replacement for the standard File Explorer program that came bundled with your phone OS.
SKTools Lite v3.3.1 SKTools Lite is a library of Registry hacks for tweaking your phone’s OS.
TCPMP (discontinued) The Core Pocket Media Player was a totally cool media player, but it was discontinued by the folks at ??? in lieu of pursuing optimization of the commercial version CorePlayer (see below).
Null Keyboard (registry) A simple registry hack that disables your Software Keyboard from being automatically displayed when your cursor lands on a text field. Really useful for those of us with hardware slide keyboards who hate seeing the SIP keyboard displayed automatically everytime we land on an input field.
Google Maps for Mobile Mapping application for obtaining turn-by-turn driving directions. Requires a data plan to access maps and obtain turn-by-turn instructions. Uses your Wireless providers cell tower to triangulate your position, but can use built-in GPS chipset if you have one.
Pocket DivX Player Plays movies that have been extracted from DVDs using the DivX format.
Pocket RAR Allows for the compression (“zipping”) and decompressing (“unzipping”) of files and folders. Supports all of the popular compression methods.
Midomi Takes sound bytes of music (such as when you hear a great but unknown song at a restaurant) and provides song details, including song title, author, etc. Also works with humming or singing a song yourself (something that the commercial product Shazaam cannot do!). Personally, I have observed very high success rates, upwards of 95% accuracy.
PockeTwit v.76 A twitter client. Simple and easy interface. Just recently updated to make use of the OAUTH function implemented by Twitter.
MyMobiler A program that creates a remote access window on your desktop PC, allowing you to use your mouse and keyboard to navigate/input into your mobile device.
Skype A popular “Voice Over IP” (VOIP) application.
Skyfire A web-browser that supports Flash 10 & Silverlight 3.0 on your Phone.
Microsoft Tag Reader A Microsoft barcode scanner that reads a proprietary version of QR codes with Adaptable size, built-in reporting and analytics (so you can see how many people are reading your tags).
Microsoft MyPhone A Microsoft application that works with a free Microsoft service to synchronize your personal data (contacts, text messages, appointments, tasks, etc) to the web. Acts like a backup server.
Microsoft Bing for Mobile A totally kickass search App for Windows Mobile devices. Sadly, Microsoft has discontinued support on most devices.
Microsoft FaceBook App A Microsoft application to allow you to access your Facebook account.
mobiletag is an Ad-sponsored UPC Barcode reader and lookup tool. I noticed that it only works reliably to auto-focus on a barcode within the first 15 seconds after the program is started. After that, it appears to stop trying. I wish there was a Commercial/Paid version of this program, I would buy it.
ArkSwitch I really like this Task Manager