Creating a resilient web business

I am getting ready to launch a new application with a business partner. I am the technical founder and only developer at the moment and want to make sure the business is resilient as far the app is concerned. I have the app in a private github repo, it's hosted on heroku, but all the development is done on my personal computer, which is backed up. God forbid if I get kidnapped by aliens or worse, I want to make sure my partners will be able to access and continue operating the app? Could someone point me to best practices concerning this issue?