Org Installable Apps

Roll-Up Helper

https://appexchange.salesforce.com/appxListingDetail?listingId=a0N30000009i3UpEAI

Mass Action Scheduler 

Create scheduled actions, declaratively and without code.

https://douglascayers-org.github.io/sfdx-mass-action-scheduler/

Declarative Lookup Rollup Summaries (DLRS)

https://github.com/afawcett/declarative-lookup-rollup-summaries 

Rollup information between Lookup relationships not previously possible without writing Apex Triggers

Enhanced Related List

Configure the Filter, Sort, and Fields on this reusable component on any lookup records to group relevant records in a single page (eg: Open and Closed Cases).

https://appexchange.salesforce.com/appxListingDetail?listingId=a0N3A00000FYDY4UAP