City-building game Megapolis led our list of emerging Facebook applications by monthly active users this week reaching 770,000 total MAU.

We define emerging applications as those that ended with between 100,000 and 1 million MAU in the past week. This week’s top apps grew between 90,000 and 480,000 MAU, based on AppData, our data tracking service covering traffic growth for apps on Facebook.

Top Gainers This Week

Name MAU Gain Gain % 1.  Megapolis 770,000 +480,000   + 166% 2.  My Christmas Tree 2012 520,000 +240,000   + 86% 3.  PNP – Portable North Pole 770,000 +210,000   + 38% 4.  Mis Fotos 380,000 +200,000   + 111% 5.  Legends: Rise of a Hero 470,000 +190,000   + 68% 6.  My Photos+ 940,000 +190,000   + 25% 7.  Fox News 170,000 +167,000   + 5,567% 8.  The Fan Machine 790,000 +150,000   + 23% 9.  SkillPages 740,000 +140,000   + 23% 10.  Wordox 960,000 +140,000   + 17% 11.  Amazon Sweepstakes 220,000 +130,000   + 144% 12.  Any.DO 240,000 +130,000   + 118% 13.  Marketland 730,000 +130,000   + 22% 14.  KartWorld 920,000 +130,000   + 16% 15.  Wrapp 650,000 +110,000   + 20% 16.  Ruzzle 780,000 +110,000   + 16% 17.  Glimpse by TheFind 490,000 +100,000   + 26% 18.  Cupid 670,000 +100,000   + 18% 19.  Pool Billiard 870,000 +100,000   + 13% 20.  Amores Ideales 130,000 +90,000   + 225%

With the holiday approaching, Christmas apps My Christmas Tree 2012 and PNP – Portable North Pole took the No. 2 and No. 3 spots, respectively.

No. 7 Fox News is back up to 170,000 MAU after a period of inactivity.

No. 11 Amazon Sweepstakes reached 220,000 MAU during its Naughty or Nice Giveaway, which ended Thursday. Five first prize winners will get $10,000.00 in Amazon.com gift cards and diamond earrings. Another five second prize winners will also get $10,000 gift cards but instead of the earrings, they’ll get a lump of coal.

No. 12 Any.DO is a web and mobile app help people manage tasks and get reminders about things they have to do.

Some social commerce apps are on the rise this shopping season. No. 15 Wrapp is a mobile gifting app where users can give gift cards to their friends. No. 17 Glimpse by TheFind is an Open Graph app where users can browse items based on what they and their friends have Liked. Users can share items they “glimpse” and save to their catalogues.

All data in this post comes from our traffic tracking service, AppData. Stay tuned next week for our look at the top weekly gainers by monthly active users on Monday, the top weekly gainers by daily active users on Wednesday, and the top emerging apps on Friday.