Robert, so sorry to hear about your loss and way to channel that passion into hopefully making a difference.
I think it's totally possible to run a Crowdfunding campaign for your app, but you should do some research as to which community / marketplace will be receptive to your idea. I'm a big believer in Kickstarter (about to back my 100th project) and crowdfunding, in general.
If I were starting this project I'd start with the data points I could gather and size the market / look for comps or signals that you're type of app / project has an audience on kickstarter:
- evaluate the apps that have funded on a given platform
- look at their category (i.e. games, productivity etc.)
- look at the number of backers it took to get funded
- the total amount raised
- number of reward tiers and price points
- i'd also do this for a couple other platforms like crowdtilt and indiegogo to make sure my project is in the right place.
Once you've validated that you need to build a list of your first 1000 backers and get them primed to support you when the campaign launches. Assuming you get a little pop of backers, then you need to figure out how to keep driving traffic to your campaign over the life of it.
The story behind the app is compelling and should resonate with a broader internet community (e.g. It Gets Better). If that's supported with a compelling product, and some meaningful support tiers then you might have a good shot at it. It's going to be hard regardless. Kickstarter and other sites are noisy now, you still need to find the market, and that's traditional web marketing, growth tactics and some good old fashion PR.
If I was going to start today, I'd start building that list. It's the core around which the success of the campaign is packed.
I've written more detailed posts on other KS / Crowdfunding threads, which have more information about the tactics I've used (which may now be dated / no longer viable).