Where's my app? is a utility app from Microsoft that aims to help new users, who have switched from an Android device or an iPhone, to find their favourite apps on Windows Phone. Rather than offering a comprehensive listing of apps the utility concentrates on providing information for the most popular apps, an approach that feels more accessible than some app switching tools (and should also serve the majority of use cases).

For each app listed Where's my app? will, if available, list the direct Windows Phone equivalent (or let you know if it is "coming soon"). If no so match is available, it will suggest similar alternatives, but it also provides a way to send requests to app developers in order to encourage them to developer for Windows Phone. 

Taking advantage of Windows Phone's notification and Live Tile system, there is also a feature that will automatically notify if one of the top requested apps becomes available for Windows Phone, potentially a useful way to keep up to date with big app releases.

Microsoft already offers a tool, Switch to Windows Phone, that aims to ease this switching-from-another-platform scenario, but, as we described in an earlier story, it requires more effort to use (installing and running multiple apps): 

Microsoft has published twinned "Switch to Windows Phone" apps on the Google Play and Windows Phone Store. On Android devices the app will first check to see what apps are installed and then check whether they are available on Windows Phone, before returning an apps available on Windows Phone percentage. The results can be saved, so that they can later be retrieved using the Windows Phone version of the app, which provides links to quickly install the matched apps.

By contrast, Where's my app? takes a more informal approach and might better be described as an app recommendation tool geared to those that, having switched from another platform, are looking for the Windows Phone equivalents of popular apps without wanting an app-by-app matching tool. Even longer term Windows Phone users might want to take a look as it offers a handy reminder that the app ecosystem on Windows Phone is getting stronger, and that the last six months have seen some significant app releases.

Windows Phone Store description:

This utility makes it easy for you to find the Apps you are looking for. It provides App availability status and highly-rated alternatives if the App you are looking for is not available. You can also send requests to app developers, encouraging them to develop for Windows Phone, if your App is not listed as ‘coming soon’ and even notify you if one of top requested Apps become available in the Windows Phone Platform.

This App does not replace the Store and does not represent the full store catalogue, but instead, it focuses on searching within the most popular Apps for Android and iPhone and looking for availability or alternatives within the Windows Phone platform. Please tell your friends about this cool new utility, available for FREE from the Windows Phone Store!

Where's my app? can be downloaded from the Windows Phone Store for free. It is currently only available in the US.

Thanks to AJ for the tip.