• Introduction
• Features
• Usage
• Limitations/Issues
• SSL handshake failure
• Android Device IDs
• Google Checkout countries
• Screenshots

Introduction

Note: Requires Android 2.2 (Froyo)

An essential app for independent Android developers and small/medium publishers. Integrates data from Android Market with Google Checkout to provide sales insight (see screenshots below).

Features

• Get notified of low-rated Market comments
• Plot revenue across apps over time
• Quantify how comments affect sales
• Observe effect of app pricing on sales

I also threw together some slides about the application architecture.

Usage

This app is best suited for developers with less than ~100K app purchases, since caching data from Google Checkout may take a long time, depending on sales volume. If synching a large batch of records, you may want to plug in and find wifi. Caching the ~3K sales records used in the screen grabs below took about two and a half minutes.

Using the app entails:

1. Specifying a date range to plot
2. Letting the app download records from Google Checkout
3. Consolidating (automatically or manually) different versions of the same app
4. Viewing/sharing the plot

Only transactions marked as "Charged" (as opposed to "Cancelled" or other statuses) on Google Checkout are counted.

Another feature of the app allows you to specify a "rating" threshold for each app to be notified about. If a user leaves a comment with a rating at or below the threshold, you will be alerted in the notification area. You can then click the notification to read the latest comments.

Here's a direct market link if you're browsing on a phone.

If you want, you can compile the source yourself:

svn checkout http://chartdroid.googlecode.com/svn/trunk/devrev/app developer_revenue_analysis

Limitations/Issues

SSL handshake failure

Occasionally users have encountered the following error when downloading records:

SSL handshake failure: I/O error during system call, Unknown error: 0

It may be due to Issue #2690 in Android, which has a fix in the pipeline. My workaround has been to switch from a 3G connection to a Wi-Fi internet connection.

Android Device IDs

To interface with the Android Market through its API, you must have a valid device ID. If your phone has been rooted and/or has gone through a factory reset, it is possible for the phone's device ID to one not recognized by the Market. If this happens you will need to manually input a valid device ID into the application.

A device's ID can be obtained through the following code snippet:

String android_id = android.provider.Settings.Secure.getString(
	context.getContentResolver(),
	android.provider.Settings.Secure.ANDROID_ID);

Google Checkout countries

Not all countries support the Google Checkout API, and thus do not provide a "Merchant Item Key". Developers from these countries are out of luck, for now.

Screenshots