There is a new accessory for the Ricoh GR III camera: JJC metal thumbs-up grip TA GR3 available for sale on Amazon and eBay: Check out also their Ricoh GR II lens cap: and the JJC ultra-slim multi-coated UV filter: Additional pictures of the thumbs-up:
Ricoh released firmware update version 1.20 for the GR III camera (now in stock at Adorama, B&H and Amazon). Here is the list of changes (additional information is available here):