Back to the usual review this week, after our 20 Essential Apps list last Friday. Thankfully, it's been a pretty good week in the store, with lots of actually useful apps—including a full-fledged four-track recorder and a couple of utilities that actually add some usable core features that I wish would have made it into the 2.2 software update today. Oh, and of course, something Japanese and crazy. Onward!

Four Track: Remember how Keith Richards always said he recorded the riff to Satisfaction on a hotel answering machine? Well, now, budding Keefs can multi-track their sudden inspirations for songs about not getting sufficiently laid. Four Track offers all the controls you would want for a basic deck, has no track length limit, and can sync via wi-fi to import you recordings into Garage Band or Pro Tools. Awesome. It's $10.

Save My Docs: Safari received some nice performance and UI tweaks in 2.2, but it still does one thing a mobile browser should never do—wipe out version of pages you've already loaded for no reason. Multiple times I've loaded a long Wikipedia article on something that I planned to read on the subway, only to find the page totally blank a few minutes later for no explicable reason. Save My Docs does one thing—saves any document loaded in Safari locally, complete with images, to be read at any time later. $2

CalToDo: I can't believe this isn't a native feature: CalToDo easily syncs your OS X to-do lists (found in Mail and iCal) via a lite server app that runs on your machine. Interface is nice, and so is the simplicity. $1

iMarimo: And iMarimo, what can I say? It's floating ball of algae in front of a few blurry pictures that you can spin via touch. Apparently, the Marimo algae is beloved in Japan for its freakish, perfectly spherical growth and its ultra-rarity—found only in a single lake in Hokkaido. Damn. That's about all I can say about this on a Friday, and it costs $1.

This week's app coverage on Giz:

• iPhone 2.2 Update Review: Go Get It Now

• Pocket Jockey iPhone Game Simulates Horse Racing In Most Suggestive Way Possible

• Numberkey Transforms iPhone Into Sweet Wireless Numberpad

• Google's iPhone Voice Search Mobile App Now Available

• OpenTable iPhone App: Easiest, Most Soulless Restaurant Reservations Ever

• iPhone's Gas Cubby Car Care Tracker Is Anal So You Don't Have To Be

• Hands-On With Newber, The Location-Aware Call Redirector For Your iPhone

• Even Google Gets Shafted By Apple's Ridiculous App-Approval Process

• iPhone's Puzzle Quest Hits December For $10 [Kotaku]

This list is in no way definitive. If you've spotted a great app that hit the store this week, give us a heads up or, better yet, your firsthand impressions in the comments. And for even more apps: see our previous weekly roundups here, and check out our original iPhone App Review Marathon. Have a good weekend everybody.

Contact information for this author is not available.