I've made some upgrades and fixes to my Salesforce Field Usage Extension.

CSV export

Before running a scan, it displays an estimate of how many API calls will be consumed and how much of the daily API limit remains.

Candidates for Removal: shows the least-populated fields below a X% threshold.

"Where is this field used?" button that pulls data from the Metadata Dependency API

Now shows usage stats by record type.

Flags unused picklist values.

Fixes: remembers selections per org, exact record count (it was an estimate before), no longer confuses fields belonging to managed packages, , added tests, several minor fixes to labelling and cleanup.