On the first official day of Q3 2009, which established apps are still growing the most quickly? Here are the numbers from AppData on today’s fastest growing applications on Facebook in the 1 million to 10 million MAU category.

Currently taking the #1 spot is FARKLE, an addictive dice game developed by Facebook app shop Viral, s.r.o. For each game, users roll dice 10 times and try to maximize their scores by following the game’s scoring rules. As you play, chips are earned along the way. They can also be earned by inviting your Facebook friends to play the game, sending your friends who are also users of the app a gift, and/or completing offers on the app’s offer wall.

		Name	MAU	Gain	%	Developer
1.		FARKLE	2,096,924	+197,165	+10.4	Viral, s.r.o.
2.		Barn Buddy	3,188,649	+167,087	+5.5	TheBroth, Inc.
3.		Waka-Waka	3,109,541	+120,994	+4.1	Metrogames
4.		Restaurant City	5,861,728	+106,605	+1.9	Playfish
5.		Biotronic	3,398,277	+101,750	+3.1	Metrogames
6.		UNO™ BETA	1,858,228	+100,639	+5.7	GameHouse
7.		Do you really know me?	1,865,635	+57,851	+3.2	How well do you know me
8.		Know-It-All Trivia	3,707,469	+57,736	+1.6	CrowdStar
9.		YoVille	7,857,944	+44,582	+0.6	Zynga
10.		Street Racing	2,904,532	+43,082	+1.5	Zynga
11.		Bejeweled Blitz	4,404,078	+35,434	+0.8	Popcap Games
12.		Fortune Products	3,504,943	+31,957	+0.9	QuoteMountain.com
13.		Daily Horoscope	4,152,067	+28,981	+0.7	6 waves
14.		Tattoodle	1,262,829	+25,777	+2.1	Make The Web Better
15.		Are YOU Interested?	2,640,198	+23,095	+0.9	SNAP Interactive (Ticker: STVI)
16.		Is Cool by cafe.com	2,221,961	+19,652	+0.9	Cafe.com
17.		Geo Challenge	3,695,910	+19,336	+0.5	Playfish
18.		All About Me	1,436,420	+18,857	+1.3	Lih Chen
19.		SuperPoke! Pets	1,348,700	+17,474	+1.3	Slide, Inc.
20.		Rock Legends!	1,061,607	+17,192	+1.7	Serious Business

FARKLE’s approach to incentivizing friends with the app pushes the boundaries of Facebook’s platform incentivization rules. About a year ago, the Facebook Platform team prohibited incentivized invites within apps – a policy designed to increase the quality of messages sent to users via apps.

Also in the Top 5 are Barn Buddy (TheBroth, Inc.), and verified apps Waka-Waka (Metrogames), Restaurant City (Playfish), and  Biotronic (Metrogames again). The top five spots are all taken by social games, and it’s notable that three out of the five apps are verified apps – one indication that apps in the Application Verification Program are enjoying the benefits of increased prominence.

Do you really know me? and All About Me have also earned places in the Top 20, consistent with numbers from last month showing that simple quizzing apps are continuing to see some pretty viral growth.