https://lit-caverns-34623.herokuapp.com/
Upload spreadsheet data to your firebase app. It generally works for files with up to 30,000 rows, but larger files will lead to a heroku timeout.
The only assumption made about the spreadsheet form is that all column names, which will be keys in firebase, are on the top row.
To get started run:
bundlerake db:createrake db:migrate
To run the tests:
rake db:test:preparerspec
Before uploading a spreadsheet, make sure your firebase app gives full write access.