“Foursquare Day” Proclaimed in New York — Mayor Mike Bloomberg has announced that April 16, — 4/16, the fourth sixteenth of the year - to be “Foursquare Day” in New York City. Events include a myriad of check-in events from around the world.

Urban Airship Releases In-App Purchase Solution for Android — Mobile services platform, Urban Airship has announced the launch of a new in-app purchase solution for Android. Google released in-billing to consumers last month, but developers are required to host and deliver their own content. Urban Airship will help host content that goes above the Android Market’s 25 megabyte limit.

GREE & mig33 Announce Partnership — Japanese mobile social gaming platform GREE and mobile community mig33 have teamed up this week. With the partnership, GREE has opened its GREE Platform for smartphone, which mig33 will make use of, allowing games to be easily deployed on the platforms of either company.

World of Goo Hits iPhone — The popular iPad physics-puzzle game, World of Goo has come to iPhone this week. The 2D Boy-developed game is already proving popular at $2.99 and is already #2 on the top paid and grossing iPhone apps lists behind Angry Birds Rio and Tap Zoo respectively.

UberMediaPartners with 50 Cent — Developer UberMedia has announced the partnering with hip-hop record label, G-Unit Records and the launch of Uber50. It is a new 50 Cent-branded Twitter theme for UberSocial for BlackBerry.

Tweetbot Launches – Shoots Up the Charts — Developer Tapbots has launched a new Twitter client app for iPhone this week by the name of Tweetbot. Incorporating features such as gesture controls, customizable navigating, and push notifications the new title has already reached #11 on the top grossing iPhone apps list.

Color Scores Movie Deal with Water for Elephants — Social iPhone photo application, Color has a bit of a movie deal with Water for Elephants. On Saturday night, there will be an online world premiere where the Color app will be used to present a live feed of photos from the event.

Skype for Android Privacy Vulnerability — A warning to Android users, as Skype has identified a security issue with its Android application. Though they are currently working on a fix, malicious third-party apps could access locally stored Skype for Android files; which includes personal profile information.

Flipboard Raises $50 Million — According to BoomTown, at All Things Digital, Flipboard, the social media reading, magazine-style app for iPad, has raised $50 million in a round of funding. The valuation is noted at $200 million.

Games Top Tablets — According to Google’s AdMob division, games top the app usage on tablets. Of the 1,400 American tablet owners surveyed, 84% play games, 78% use tablets for searching, 74% use it for email, 61% news, 56% for social networking, 51% watch videos or listen to music, 46% read eBooks, and 42% shop online.

OnSwipe Makes Mobile Browsing “Swipe-Friendly” — TechCrunch has highlighted and interesting new digital publishing tools company called OnSwipe. The startup has recently demonstrated a new tool that makes web browsing from a mobile device work with swiping as if it were an actual app. The tool already works as a plugin for WordPress.com blog.

We City Adds Century 21 Brand Promotions — Social-mobile city-builder, We City, from developer ngmoco, is adding in a promotion from real estate agent company, Century 21 (with the help of appssavvy). Until April 26th, users can purchase branded Century 21 buildings for their virtual cities.

InMobi Releases New Insights Report — InMobi has released its most recent Global Network Research report, and for the first time, on a global basis, Android has surpassed iOS. The former now holds 14.5% of global impressions on the InMobi network. More information and the report can be found here.

Companies Struggle to Hire Mobile Talent — As the mobile space becomes more lucrative, the demand for talented mobile developers is growing, says The Wall Street Journal. However, with constantly changing technology, the individuals to hire from is not growing as quickly. Simply put, not many potential software engineers have the knowledge and experience due to the relative newness of mobile tech.

American Express Partners with Payfone — According to EngageDigital, credit card company American Express has partnered with mobile payment firm Payfone to allow users to make online purchases using their mobile phone number, using its Serve payments platform. In addition to this American Express has also announced the investment of an undisclosed amount in Payfone.