Textopia is an open source mobile mapping application for Android, it is basically a location-based audio player. It demonstrates a lot of KML data source functions.
Take a look to Textopia Mobile application general info or get current state of development on Textopia Android Google Code project page
EMT map of Estonia is implemented by Nutiteq in top of NutiMap toolkit. It is a customized Java ME mapping application as part of mobile operator LBS portfolio. Special features include mobile positioning (with Ericsson MPS, Spatial Triggers and Reach-U LBS MW), POI content, favourites, GPS positioning and routing for a mobile operator.
Trapster, speed camera location sharing application, is currently the most popular mobile application with MGMaps Lib SDK included.
Our team has implemented BlackBerry and Java ME client for that. Other guys have made also iPhone version.
More info and download it for free:
http://www.trapster.com