OneMerge Free Edition and OneMerge Standard Edition are available from the Salesforce AppExchange. You can install a trial version which is supported by documentation on the website and also watch a demo. The trial version also is supported by example Test Scenarios that you can execute to become more familiar with OneMerge.
Test Scenarios for OneMerge Standard Edition:
Scenario 1. Real-time merge for duplicate Person Accounts.
Scenario 2. Data Stewarded merge for duplicate Person Accounts.
Scenario 3. Custom merge for duplicate Business Accounts.
Test Scenarios for OneMerge Free Edition:
Scenario 1. Scheduled merge for duplicate Person Accounts.
Scenario 2. Scheduled merge for duplicate Leads.
The Following Training Articles provide information for the Installation Instructions and the Configuration steps for OneMerge Free Edition and OneMerge Standard Edition:

The support provided for both editions is comprehensive, and if you would like further help or to discuss the products further, you can reach out to hello@onemerge.co.uk. We also offer a courtesy QuickStart call to discuss your requirements and provide expert setup guidance. If you would like to schedule a demo, you can do so by completing the contact form on the website.
Please do get in touch if you need any help with anything OneMerge Free Edition, Standard Edition or OneMerge Enterprise Edition related. You can also follow using on X and Instagram @OneMergeApp.