One of the first things I did when I got my DroidX was visit the android marketplace to see what kind of apps they had for knitters. Sadly, it's small pickings there and honestly, I've barely used the apps I've downloaded.
Ravulous is the first knitting app to use the Ravelry API. Right now, you can only view and edit your current projects. This is good if you just want to quickly update as your knitting, or if you want to show a friend what you've been working on.
Knitting Calculator is a bit simplistic, but still worth the .99 British Pounds to purchase for those random times you need to know whether you have enough yarn for a project. It has inputs for the yarn that the pattern requires, and then you input the total yards per ball/skein of the yarn you wish to use. Voila, you have the word as to whether or not you have enough yarn. Handy to have in a pinch.
(scan the box using your android camera to download)
Yarn Shopper is another nifty android app for knitters. It's 1.50 for the non-ad version. You can keep track of the knitting projects you wish to knit, adding the required yardage and yarn weight and Yarn Shopper will tell you which yarns would work for the project, how many you would need and the total cost to buy the yarn. This app would be the knitter's holy grail if you could actually purchase the yarn as well. Here's another, more detailed review from Nicole Torres at Absolutely Android.
Tally Bee is another cool thing to have on hand, it's basically a simple counter that one could use for anything, but for knitters it turns your android phone into a very expensive row counter :). I wish you could save and name multiple counts for different projects.
Knit Cards seemed like a cool app, but I didn't enjoy the prospect of re-entering projects that I had in ravelry into a wholly different app. I'm just going to wait for Ravelry to come out with their own app.
Speaking of coming out with apps, I'm looking for a simple android app for KnitLuck. Are there any developers out there who could help me out?