I have already devoted some time to exploring Windows Phone 7 apps in general, and I have praised the fact that this mobile platform offers an option to try an app before you buy it in many cases, but today I am going through my iPhone app by app to outfit my Windows Phone 7 "Mango" smartphone as closely as possible with the apps I am already used to.

I am not replacing everything. Switching platforms is a great excuse to clean house and eliminate some app clutter. I have about 120 apps on my iPhone, but I really only use 10 or so on a regular basis--maybe 20 of them on a weekly basis. Some apps have rarely, if ever, been used since I installed them on my iPhone.

Some of the tools I use regularly are just core apps that come pre-installed in Windows Phone 7. Things like Alarms, Calculator, Calendar, and Camera are already there, so I don't need to find replacements. I frequently use my smartphone to look things up on the Web, and Windows Phone 7 has the Internet Explorer browser pre-installed, so I am all set there.

Next on my list of common smartphone tasks are social networking, and entertainment. Facebook, Twitter, and Foursquare all have official apps for Windows Phone 7. Google+ and LinkedIn do not. There are some third-party apps for LinkedIn, and maybe even for Google+, but I will just use the browser for those until an official app is launched. As I noted on Day 7 and Day 9, though, the integration with the Messaging app and the "Me" tile make separate apps for the social networks redundant and uneccessary.

When it comes to entertainment, I rely on apps like the Kindle app from Amazon, the Netflix app, the YouTube app, and other tools like Fandango and IMDB. All five have Windows Phone 7 apps, and all five are free. So far, I am doing pretty good and haven't spent a penny.

For productivity on the iPhone I have the Apple iWorks apps--Pages, Numbers, and Keynote--as well as Documents To Go. With Windows Phone 7, I have Office Mobile apps installed with the OS, and integrated with cloud-based file storage on my SkyDrive, so I don't need to replace those apps.

I struggled with navigation. I deleted the pre-installed AT&T turn-by-turn navigation app because I'll be damned if I am paying AT&T $10 a month for that service. The Maps app in Windows Phone 7 is pretty slick, and it does directions, but it requires me to tap after each step rather than monitoring my location and automatically telling me where to go, or recalculating if I miss a turn, or diverting me around traffic backups.

I really like my Garmin StreetPilot app on my iPhone, so I searched the Windows Phone 7 Marketplace and found that Garmin has the same app available here as well. The problem is, I had to spend another $35 on it.

For mobile banking, I am going to have to rely on my bank's website. I bank with Chase, and Chase doesn't have a Windows Phone 7 app. It's a shame, too, because the iPhone app lets me deposit checks by taking a picture with the iPhone camera, and now I am going to have to actually go to the bank to deposit money.

I also had to go through and replace some of my games from my iPhone--Tetris, Angry Birds, Need for Speed, Sonic the Hedgehog, and others. Unfortunately, Electronic Arts hasn't yet created Windows Phone 7 versions of my favorites--Madden NFL, and Tiger Woods Golf.

I am going to digress from Windows Phone 7 for a minute to get on my soap box. It would be nice if app purchases were cross platform. In other words, if I have given my money to an app developer--say Rovio for Angry Birds--and I ditch my iPhone for a Windows Phone 7 smartphone, it would be nice if there was a system in place to allow me to take the investment I already made in the app, and roll it to the new mobile platform.

I know it's a pipe dream. I know that just isn't the way things work. I mean, if I switch from Windows to Mac OS X, Microsoft isn't going to just give me a free copy of Microsoft Office for Mac OS X just because I've been a loyal Office user on Windows. I get it.

Without such a system, though, it makes it a more difficult decision to switch platforms. Many of the apps I used on my iPhone are simply not available on Windows Phone 7, or they are free apps--like the Facebook and Twitter apps. But, just for the small subset of apps that have a Windows Phone 7 equivalent and cost money, I had to spend $75 buying apps that I already own.

Of course, with Windows Phone 7 that investment is offset somewhat by integration of Microsoft Office apps that replace my investment in iOS apps like Pages, Numbers, Keynote, and Documents To Go. In the end, I was able to find direct equivalents for most of the crucial apps I rely on. With 30,000 to choose from, I am sure I can find what I need for almost every purpose.

Summing up the experience, I would say that the majority of apps that I really need, or actually use have Windows Phone 7 equivalents available--the most notable exception being the Chase Bank app. As for the rest of the apps, with 30,000 to choose from I am pretty sure it won't take me long to find apps I like and get back up to that 120 range.

Read the last "30 Days" series: 30 Days With Google+

Day 9: It's All About "Me"