A shuin (朱印) is a seal stamp given to worshippers and visitors to Shinto shrines and Buddhist temples in Japan. The seal stamps are often collected in books called shuincho (朱印帳) that are sold at shrines and temples.(from Wikipedia)
Each shrine and temple has its original shuin and shuincho. There are not a few collectors of shuin in Japan.
A Japanese company, DO THE SAMURAI, provides the “Shuincho Map of Japan” service.
You can see a shuincho of each shrine and temple.
The picture and comment of shuincho has been posted by the service users.
This “Shuincho Map of Japan” is a new function added to the “Hotokami” web service, which consists of users’ posts about shrines or temples that they visited.
There are about 160 thousand shrines and temples in Japan. They say that most of them don’t own their website, so it’s difficult for them to get new visitors. In this situation, about 40% of shrines and temples will diminish by 2040. The company has launched the service in order to tackle this problem. They hope that the service will help those who are interested in visiting shrines and temples to find a new place and also stop the number decreasing.