Metabase is my new favourite tool: I've probably use it every day to answer some question instead of dropping into the Rails console. Things like: what percentage of orders come from Stripe vs Paypal? Or export a list of users that match this criteria. Or display the top 10 users by some metric.

It makes creating BI charts from a database easy enough that a non-developer can do it. But when the going gets tough, I can still drop down to hand-coded SQL. It was also an easy installation on Heroku.

It's not entirely perfect (combining multiple series on one chart is harder than it needs to be; can only pull data from databases not APIs) but it's been a success so far