There is a new free GRImageViewer iOS app for transferring photos from the Ricoh GR III camera to iPhone/iPad that offers also some additional functionality and features:
Browse photos of your GR III camera via WiFi.
Beautiful grid layout for photo browsing.
View photos by date.
Transfer photo or a collection of photos from your GR III to your device.
Multitask photo transferring (up to 4 downloads simultaneously).
View photo metadata: iso, aperture, file size, etc.
Dark mode supported.
Show new photo(s) since last time connected to the same camera.