Google Play apps are earning much more now than they did just six months ago. According to app store analytics provider App Annie, Google Play revenues increased by 137 percent during the first seven months of the year — a trend several developers with apps on Google Play are seeing in both the domestic and international markets.

According to San Francisco’s TinyCo — which has long touted its ability to monetize on Android and has been showcased by Google as an Android success story — its free-to-play title Tiny Village is still earning more on Android and seeing better retention than it does on iOS.

According to TinyCo’s head of product Rajeev Nagpal, the game is currently seeing 20 percent higher average revenue per paying user (ARPPU) on Android. In addition, for the past two months the game’s average revenue per weekly active unique has also been higher on Android than on iOS. More importantly though, he explains, conversion rates have been improving rapidly on the platform.

“Payer conversion, which we believe to be the final frontier on Android, is getting progressively better and is almost in kissing proximity to that of iOS platform,” he says. “The shift has been very exciting and encouraging for us.

While Nagpal believes there are probably numerous reasons behind the increase in Android conversion rates his company is seeing, its likely at least some of the increase is to due to Google’s savvy use of sales to promote app purchases. In the past 12 months the company has tied three milestone app store events to massive sales that discounted the price of popular paid titles to just a few cents.

As we’ve said before, it’s a smart strategy that’s helped the company round up a lot of payment information — back in March sources told us that the first sale in December 2011 was able to add credit card information for 1 million new customers — convincing many Android device owners to make their first purchase. As the iTunes App Store and Amazon’s App Store have proven, once a consumer is set up to make near frictionless payments, they’re far more likely to keep making them. Google also packaged its popular Nexus 7 tablet with a $25 Google Play gift card that required the user to add their credit card information before they could redeem it.

We also reached out to the Android-only Animoca to see if the company — notable for its high-volume “app supermarket” strategy — had seen it was also seeing its apps earning more now than they were at the beginning of the year.

According Sunny Cha, Animoca’s senior manager of marketing and corporate development, her company has seen its average revenue per daily active user (ARPDAU) increase by a significant margin in both domestic and international markets.

“We’re seeing a faster rise than what App Annie is reporting,” she explains. “Not only ARPDAU, [we’re also seeing] an increase in total download volume across the board. ARPDAU for Google Play is still behind Amazon and T-Store (the third-party Android App store operated by South Korean mobile provider SK Telecom) but it’s catching up.”

Cha reports that in markets where carrier billing is prominent like Japan and South Korea, Animoca isn’t seeing a significant increase in ARPDAU (as those markets already monetize at an extremely high rate), but like TinyCo it is seeing a noticeable uptick in the number of transactions, which has also contributed to rising the company’s revenues.

South Korea’s Com2uS also echoes the sentiments of Animoca and TinyCo. “Google Play is definitely a fast growing market,” explains Don Lim, the company’s U.S. general manager. “T-Store and Google Play are the two biggest Android markets in Korea, and Google Play is growing at faster rate this year.”