I wrote a native Android application called Respond after the Haitian earthquake. When the earthquake hit, you might recall there was a tipping point reached in mobile giving via short-codes. The $10m given was 10 times the previous record. From this, we saw a need for people to have a discoverable app in the stores that pointed them to ways to contribute to relief and get informed in times of crisis without the wait for app store approval. The app content can be instantly updated, as it was after the disaster this year in Japan.
Looking back, this app could have been written with a framework like Sencha Touch on top of PhoneGap, but it was worth a little extra time to dive into Java.