While applications for change certainly has the best ring to it -I would be wary of the political weight of the word 'change' right now. I think something more neutral would have more longevity/relevance.
I propose a new name: RedxApp. (Read: Red Cross App) which is true to its name, a website that is meant to help people, just like what red cross does)
I simply love the word "Change" so I voted for the #2.
Second choice would be applicationsforchange...apps just feels more current. Also, this preference hinges on the double meaning of change as social good and as money...assuming the sponsorship involves some sort of compensation to the developer.