There’s been a lot of change on the breakout app radar this week, and a diverse set of apps are growing quickly on the Facebook Platform.

Here’s the current list of Top 20 fastest-growing mid-sized applications on Facebook from AppData. These are the top apps in the 100K-1M monthly active user range with the most growth in the last week.

		Name	MAU	Gain	Gain, %	Developer
1.		ExitReality 3D Apartment	284,969	+282,026	+9 582.9	—
2.		2009 Bracket Challenge	146,674	+143,705	+4 840.2	Watercooler
3.		Cheers!	186,331	+161,757	+658.2	—
4.		Deal or No Deal	290,579	+225,698	+347.9	Tyrone Walker
5.		Super Mario World	102,206	+70,638	+223.8	Ankur Nagpal
6.		Jeu de Seduction	457,971	+213,375	+87.2	6 waves
7.		Praise Party	102,192	+40,088	+64.6	—
8.		DogWorld	146,126	+55,009	+60.4	—
9.		I’d Have To Be Drunk	118,118	+43,614	+58.5	Colin Kierans
10.		Sei Affascinante	267,307	+97,788	+57.7	6 waves
11.		ViP Club$	154,763	+55,433	+55.8	Arnaud Gufflet
12.		Send “Willow Tree” Angels	187,263	+61,550	+49.0	—
13.		Eres Atractivo	394,042	+117,605	+42.5	6 waves
14.		u00c7ekici Misiniz?	251,766	+69,534	+38.2	6 waves
15.		Which mighty woman of the Bible are you most like?	130,302	+30,633	+30.7	Lara Melinda Jones-Leger
16.		Tiddy Bear for Cancer	233,513	+52,698	+29.1	—
17.		Send Good Karma	136,649	+30,428	+28.7	—
18.		型男vs索女	138,456	+30,376	+28.1	6 waves
19.		80′s Memories Gifts	287,104	+62,339	+27.7	—
20.		Say Something	271,055	+57,629	+27.0	Offline

As you can see, an application called ExitReality 3D Apartment has absolutely skyrocketed in the past 2 days from 0 to 300k active users. However, the application appears to only prompt users to visit an external website which contains a cryptic message about “gathering data.” Smells fishy to us, and we’re sure Facebook’s policy folks will be taking a closer look at this one soon.

Coming in at #2 this week is Watercooler’s 2009 Bracket Challenge. 150,000 college basketball fans are gearing up for the tourney already, even though Selection Sunday is still a few weeks away. Last year, Facebook promoted a bracket application created by CBSSports.com on its home page and through Inbox messages. It will be interesting to see if Facebook does a similar special promotion this year.

Filling 4 spots this week is an internationally templated application by 6 waves called Jeu de Seduction / Eres Atractivo / 型男vs索女 / etc. 6 waves has been gaining traction on the Facebook Platform by serving international audiences, and is one of the largest developers on the Platform by total MAU.

Other interesting apps on this week’s list are Ankur Nagpal’s Super Marion World, Tyrone Walker’s Deal or No Deal, and Tiddy Bear for Cancer. As always, you can find out more details on these apps and nearly 50,000 others at AppData!