Ruby Gem List

Used

Chartkick

One line charts in JS. GitHub Repo

Not used

PG Hero

PG Performance Dashboard GitHub Repo

Blazer

Allows you to query DB and generate reports from it. Looks nice GitHub Repo

Spreadsheet architect

Generates XLSX, ODS and CSV from ruby objects

Emojis

Used by Gitlab

https://github.com/jonathanwiesel/gemojione