Geeklist is currently organizing a global, virtual hackathon to work on multiple tools and ideas that will help out the people in Nepal affected by the earthquake.
For more details, see the Hack4Nepal web page. It seems that the date given there is off by one month, so the hackathon is about to start today (2015-05-02). If you find out something else, please put it into a comment below.
So far, the projects and ideas for the Hack4Nepal hackathon are not too many, but you may add your own. Personally, I find the “Is your home safe? app” idea interesting. @Natalia_Skoczylas and I discussed something similar with a Sunoj from the Karkhana hackerspace in Kathmandu; we wanted to allow civil engineers to inspect houses remotely after an earthquake, via photos made by teams on the ground or the inhabitants. It is unclear if this is safe to do though – engineers’ reactions were mixed.