Sites that provide web-based indexes of applications in the Android Market are very prevalent these days, with new ones popping up and claiming that they can help you sort out the good Android apps from the ones that are basically spam. Some of the top contenders are AppBrain, AndroLib, and AppStoreHQ.
From a developer perspective, AndroLib and AppStoreHQ can be frustrating. They do not keep updated and accurate information about your apps or are very slow to update them. If you want your app listing on their site to be update-to-date you must register with them and request they update it when necessary. The processes for requesting updates are incomplete, even requiring a manual request (email) to update aspects of the listing such as icons and screenshots. App Developers don’t have a lot of time to waste and having to keep emailing the owners of these sites to request updates and going through their processes is time consuming.
From a consumer point of view, AndroLib is the worst of these two. Usability on this site is rough and it performs poorly. Information cluttered on both AppStoreHQ and AndroLib again pointing to the usability issues of these sites. It should also be noted that AppStoreHQ does not only index just Android apps but iPhone/iPad and web applications as well.
Here is a site that nails it perfectly, not only do they automatically update all details of your app, they do so very regularly and without any intervention on your part. This is how one of these sites should be done, not only from a developer perspective but also from the view of the end user. The site is very minimalistic, performs well, and really has some great market integration features allowing you to sync your installed apps and install from their web site. Not to mention the fact that they have an Android app and they have implemented techniques to filter out those many junk/spam apps that plague app markets.
If you are looking to build one of these sites I suggest you look at AppBrain as a model first.