That's correct folks, we've reached the 20,000 app marker, which is fantastic for the platform in seven months. Our 10,000 milestone marker coverage mentioned how we were expanding at a faster rate than both the iPhone and Android. It's worth to note that the 10,000 app marker was surpassed in four and a half months (since launch) - we've since halved the time taken to get another 10K. Not to mention it's only been a month since 15,000 apps were announced!
RIM currently has little over 20,000 apps available for their platform since 2009, which we will be over-taking shortly. Will this growth continue for WP7? It certainly seems that way. Check the graph below to see the increasing number of apps being submitted, the line is becoming more steep as we advance in time.
Of course, there's always a downside to high numbers; fragmentation and spam - iOS began experiencing this when they reached the 20k marker for the App Store with a ton of LITE apps. Some of which we've witnessed lately with regards to some real estate apps (one being submitted per state), which could possibly be integrated into one offering? Let's hope the certification process starts becoming strict on these sorts of submissions to keep the Marketplace clean.
None of the above would be possible without our contribution - the wpcentral app. See, even we're helping out in the counters where we can!
Source: Windows Phone Applist