When a Revolutionary War veteran died, the heirs were eligible to claim the pension’s last payment. In order to do so, they generally had to provide support of the veteran’s date of death and their connection to him. This could come from statements from the local probate court, civil registration, and more. Because the final pension payment vouchers include the veteran’s date (and often place) of death and family relationships, they are valuable resources for Revolutionary War lineage society applications.
The index cards have long been available on Fold3. A star on the card indicated that the file could be obtained from NARA. See https://www.archives.gov/research/military/army/final-pension-payment-vouchers for details.
More recently, Fold3 has begun to digitize the files. Georgia and Delaware can now be searched on the site. If you don’t have a personal subscription, Fold3 can be accessed from some libraries. Ask your reference librarian for details.
And if you’re willing to do a bit of digging, you may be able to access the records you need for free. Many of those final pension payment voucher images have been attached to the catalog entry at NARA.