Last summer, Apple (AAPL) made headlines when it revoked the license of one of the most prolific third-party iPhone developers, a Pakistani operation called Perfect Acumen that managed to get 943 apps past the App Store review process before somebody noticed that most were nearly worthless and dozens contained blatant copyright violations. (See here.)

On Monday, Apple struck again, pulling the plug on the 1,898 apps published by Molinker, a Chinese developer that had been caught gaming the App Store ratings system, allegedly by offering free programs to users who agreed to give the apps five stars. (See here.)

Is Cupertino getting its store in order in advance of the big pre- and post-Christmas sales season?

It certainly seems to have raised its standards, rejecting silly apps — like Ka-Ching — that would have easily passed muster when the company was racing to reach the 100,000-apps mark.

Now perhaps it can start clearing out some of the spam it’s already let in. One big fat target: Brighthouse Labs, a shadowy company whose 1,855 titles clutter up the App Store’s virtual shelf space with one-off recipe-, quote-, and sports-fan apps.

Legitimate developers have long complained about all three of these companies. Together they’ve pushed nearly 5,000 applications — representing 4.5% of the App Store’s total offerings — past Apple’s reviewers, making it that much harder to find the apps that are worth buying.

For the record, here are the 10 most prolific (but not necessarily spammerific) App Store developers, as counted by 148Apps.biz‘s Jeff Scott:

1. Iceberg Reader (3,431 apps)
2. Brighthouse Labs (2,148)
3. Molinker Inc. (still on his latest list, 1,898)
4. FidesReef (1,250)
5. Your Mobile Apps Inc. (938)
6. IndiaNIC Infocom Limited (804)
7. xhumans (761)
8. Appsessions, LLC (701)
9. O’Reilly Media, Inc. (617)
10. SOFTBANK Creative Corp. (592)

[Follow Philip Elmer-DeWitt on Twitter @philiped]