Mobile location is all the rage... what better way to complement your location-aware application, web services, or online resource than by supporting one or all of the various mobile platforms.

The following are some useful Dev resources for those thinking of creating mobile apps for a variety of devices and platforms.

Apple iTunes
Apple has a community resource for developers interested in publishing to the iTunes store from the developer program housed at http://developer.apple.com. Here's developers will find a gateway to the iOS Dev Center as well as a pointer to the iOS Developer Program - http://developer.apple.com/programs/ios/ where developers have everything they need to develop, test, and distribute their apps - note, there is a $99 annual fee for membership.

Palm
Developers interested in creating and publishing apps for the Palm Web OS will find resources at developer.palm.com. The community dev resource offers access to information about the 3.0 SDK as well as information on joining the developer program Developers can also find information on downloading the latest tools and SDKs as well as the latest developer guides and docs. Of particular interest is a resource for iOS developers to enable them to quickly create and port apps to the Palm environment - see HERE

Ovi
Ovi is the marketplace developed by Nokia for users of Symbian, QT, and other Nokia powered mobile devices. See http://info.publish.ovi.com/. Resources here for developers include a gateway to Forum.Nokia, the Nokia developer community portal, Ovi publisher docs, news alerts, tips, and much more.

Android
Android Market - https://market.android.com/apps/ This is the resource for Android device users seeking out apps. Browse for new additions as well as popular free and paid for apps. Developers wishing more information on how to develop for the Android Mobile OS should start at http://developer.android.com/index.html. Resources here include documents, SDKs, reference guides, community resources and anything needed to publish apps in the market.

Blackberry
Blackberry (RIM) maintains some fine dev resources including the developer home portal (US) at http://us.blackberry.com/developers/resources/. This resource provides access to the latest downloads, docs, tools, news, event information, community resources, and more. The developer blog is also packed with useful information for mobile developers http://devblog.blackberry.com/

Amazon
Amazon App store for Android
Via the popular amazon.com resource, the company offers Android device users a place to locate and download apps. Currently the store is boasting a free Android app a day although the store is only available to US customers at this time
http://www.amazon.com/mobile-apps/b?ie=UTF8&node=2350149011

Windows Phone Mobile
Windows Phone mobile device users will appreciate the Windows marketplace from Microsoft - http://marketplace.windowsphone.com or Win Phone 7 users see here. The service is available via PC or, device users can download the app so the marketplace is available on their device. Currently the app provides a gateway to popular and suggested mobile apps (free and for sale) and a "What's New" category is handy to stay informed of the latest additions to the store. For developers interested in creating app for Win Mobile devices see the App Hub - http://create.msdn.com/en-US/ - for the latest Win Mo developer news, tips, docs, edu resources, Q&A and resources for submitting your app. 

Note: Esri also has a useful resource enabling users to extend their ArcGIS to Windows Phone 7 devices - ArcGIS for Windows Phone lets the user navigate maps, collect and report data, and perform GIS analysis. It includes a free ArcGIS app that you can download from the Microsoft Marketplace along with an API to build your own Windows Phone apps

Mapquest Developer Network http://developer.mapquest.com/
A central resource for learning about and working with Mapquest  SDKs, APIs, Web Services, Tools and Resource. Of particular interest is this starting point http://developer.mapquest.com/web/products/open

Google Maps
Developers interested in creating apps with google maps APIs and tools should start off at http://code.google.com/apis/maps/index.html where docs and information about the latest APIs are found.

Bing Maps
Developers in need of information from Microsoft about developing with Bing Maps API and tools should consult http://www.microsoft.com/maps/developers/mobile.aspx. Tons of info including tools, docs, SDKs, and community resources can be found here.

Esri Mobile GIS
Esri has a fine starting point for developers looking to build on Esri's mobile solutions. At http://resources.arcgis.com/content/mobilegis/about devs can find pointers and tools for ArcGIS Mobile solutions, ArcPad, and resources for developing ArcGIS for iOS and Windows Phone. The ArcGIS Mobile blog is also very useful

OSM
Developers needing information on working with OSM data and resources should consult the developer wiki as a starting point http://wiki.openstreetmap.org/wiki/Develop 

Other Useful Resources:

Looking for news and tips about mobile application development, dev tools, dev programs and the like? Be sure to consult this awesome news archive with a TON of information

More LBS News - iPhone Zone, Blackberry Zone, Symbian Zone, Windows Mobile, Android Zone.

We also have a useful directory of developer programs that you can take advantage of - see HERE 

10 Developer Programs/Resources of interest for LBS developers:

1. ESRI Developer Network (EDN) 
2. foursquare API and Developer Home
3. Flickr Developer Guide
4. Trimble Mobile GIS Developer Community
5. MapQuest Developer Network
6. geoIQ Developer Portal 
7. LOC-AID's Developer Zone
8. NAVTEQ Virtual Developer Lab
9. Android Developers on Sprint
10. Verizon Developer Community
    
    See Also, Developing Location Based Services (LBS) Mobile Applications