The real value of your app is not in the bells and whistles, or the css, or its 4.0 Code Climate GPA, or its client-side this and ajax-that.
It’s in the data.
The easier you make it for your clients to get their data, the more valuable you’ve made your product.
Try this: connect your client’s MS Excel to their database with ODBC. Then teach them how to use pivot charts and pivot tables to analyze the data themselves.
This solution does not require a single line of Ruby to implement, and your clients will love how easy it is to access their data.
One caveat is that the ODBC connection should be made on a read-only database user, and you have to think hard in advance if you really want your database credentials out in the wild. In the end, I actually chose to have the client download CSV files from inside the app itself, rather than using ODBC, so that I could manage authentication and who can access what through the app. But if your authorization needs are not as complex, ODBC is a great tool, and can save you writing lots of code!