I was looking for an easy way to help users find images to upload for one of my apps and found THIS BLOG that documents the URL search parameters for Google.
I was able to make a button that pulls search terms from the record in AppSheet, and open a custom image search, with options set for image type, color, size, etc:
This works for creating custom Google searches for News, Books, Videos, Flights, etc.
In my case, the formula for the URL is:
"https://www.google.com/search?q="&ENCODEURL([Species]&" "&[Variety]&" "&[Color])&"&tbm=isch&tbs=itp:photo"
tbm=isch -Sets the result type to Image, and
tbs=itp:photo -Shows only photos (no clip art, drawings, etc)
ENCODEURL() converts your column data to the proper format for the URL request.
See the blog post for more info on other search parameters.