Spreadsheet can work in IRB. Try this:
book = Spreadsheet.open(“foo.xls”) and true
book.worksheets
October 28, 2014
October 24, 2014
Using Ruby Spreadsheet on Heroku with Dynos
If you intend to use The Ruby Spreadsheet on Heroku, and your source code is closed source then 0-4 2X dynos at 100% CPU load are considered as one physical CPU (1 PX). In other words, this means that if your Software runs on Heroku, is not OpenSource and uses The Ruby Spreadsheet gem you will have to buy a NON-OpenSource Commercial License that allows you to use The Ruby Spreadsheet together with your closed-source code.
The Ruby Spreadsheet 