Which Android Platform Version Should I Target?

In other words, which API version / level should I use in the development? There are several android platforms out there and developers need to make sure their android applications are usable by most, if not all, of the users.

You can find a useful platform usage statistics here in the Android developers website. It is based on the number of android devices that have recently accessed the Android Market. Below is the current statistics captured from there.

As of now, targeting Android 1.5 would allow you to reach basically all the users while targeting Android 2.1 also seems to be a safe bet with 95.6% coverage if your application needs some of the newer platform / API features.



Update:
I have written some more notes on this topic here.

Android Application Development Journey Begins

Several days ago I decided to try to develop some android applications. I went ahead and downloaded all the required development software like Android SDK, Eclipse and Java JDK. Well, it didn't go smoothly.

After installing the JDK, I proceeded to install the Android SDK. A strange thing happened. It told me that JDK was not installed in this machine. What? I was sure I had just installed it. So I restarted my machine and tried again. No luck. After quickly searching around for the solution in Google, I found the magical solution - just click "Back" and then "Next" again and the installer would be convinced that you really got the JDK installed. It seems to be a common problem for 64 bits Windows users.

Anyway, all things were set and ready. So I followed all the steps in Google's Hello World tutorial. In the last step, I hit the "Run" button and the android emulator came up. My first program was supposed to launch automatically. However, nothing happened. My first program didn't launch at all. I couldn't find it installed in my emulator as well. All I got in my Eclipse console was:

[2011-06-03 14:21:17 - test] Android Launch!
[2011-06-03 14:21:17 - test] adb is running normally.
[2011-06-03 14:21:17 - test] Performing com.example.testtest.testtestact activity launch
[2011-06-03 14:21:17 - test] Automatic Target Mode: Preferred AVD 'AVD' is not available. Launching new emulator.
[2011-06-03 14:21:17 - test] Launching a new emulator with Virtual Device 'AVD'

And that was the end of the log no matter how long I waited. I reckoned the launching process was basically stuck there.

After searching around for the solution for quite a while, I finally found a workaround to this problem. When you are stuck like I was:

1. Open the command prompt. (cmd)
2. Go to your Android SDK tool directory. (e.g. cd "C:\Program Files (x86)\Android\android-sdk\platform-tools\")
3. Kill the adb process by "adb kill-server".
4. Then restart it by "adb shell".

Done! Your android program will now launch in the emulator. Hope this helps someone who had the same problem.

*Edit*
I had the same problem with launching my android application in IntelliJ. The launching process would stuck at "Waiting for device.". Fortunately, the above solution still works. For convenience, I have created a batch file to perform all the workaround procedures with two clicks.