Unfortunately de same n making it difficult to share device among family members...

What in case a family of 6 wants to share the device? It is very difficult to share pins or patterns with everyone. Easiest would be atleast provide 5-6 fingerprints possible so tat the device can be shared seemlessly....

feature not provided by WhatsApp developers or any other application developer groups...it all depends how each individual developer groups wants to control the phone memory usage...android developers can make changes to the OS installed on phones ho...

please try to ensure that SD card can b chosen as default in the next Oreo update released for tab s3.

pls check the file extensions as it might be thumbnail images as mentioned by @mevishnu...