"I have installed Rollup Helper in three Salesforce Orgs and have found tremendous benefits in each one. We are using almost 100 rollups in one org alone. It is easy to use, with great case uses to guide you. Their Support team is quick, patient and always willing to spend time with you. I recommend this to anyone who has to create rollup fields in SFDC.
The related applications of Lookup Helper and Storage Helper are a must as well. Lookup Helper has allowed us to cross reference leads and accounts, as well as other objects."
"This tool enabled me to replace an enormous amount of complex code with configuration. We are constantly finding new uses for Rollup Helper, and when I run into questions I get fast/helpful responses from their support team. Highly recommend."