Good for iOS, good designCons:
Bad for Android
When I have the old mobile, the Gboard was predefined, and it was a bad idea. The board has a lot of bugs, and you can not personalize like on iOS, you have limited options to have a beautiful chat board. I really like to have this on my new mobile, where iOS is completely different. The iOS original board is very clean, but you do not have some options to use, with Gboard, you have a good options!
Swipe typing; emoji search; GIF search; moving the cursor by swiping the space bar; ability to customize the colors and backgroundCons:
No Siri integration; voice transcription is supported, but it's kludgy: can be a *little* slow to load sometimes
The best custom keyboard I've used for iOS — it's now the only custom keyboard I have installed.