If you are a Florisboard user, there is a version with dynamic Material You themes here. It's really good while we wait for the new versions with this official built-in
Wow, Openboard is a huge keyboard by default with lots of vertical key spacing. It also has two of my favorite Gboard features:
Swiping left and right on the spacebar moves the cursor left and right.
Swiping left starting at the backspace key will highlight text, then releasing the key will delete the highlighted text. However, it doesn't pop-up the deleted text as a suggestion to let you undo it, in case you didn't by accident.
Unfortunately, I haven't been able to find any alternative to gboard with good hand writing recognition for Japanese... So if you need that functionality I think gboard is your only choice
You are handwriting Japanese symbols? I use the querty keyboard that converts romaji to hiragana/kanji. However I'm afraid this isn't available on other keyboards either...
What I dislike about ASK is how... disjointed it feels.
For example, I cannot use a mixed english+german input and have the same key layout for both languages. But I don't want to swap between keyboards, I need one keyboard setup to do both things.
For me, the key is FOSS. I was a keen fan of swiftkey, its word predictions worked great. Then it was bought by a company that I distrust, and when I was forced to choose another, I decided to try to ensure I'd never have to switch again.
A little while after I bailed on swiftkey, the news reports came that it was auto-filling random strangers' credit card numbers; I felt vindicated.
I'm always looking for an android keyboard that is either only a number pad, or can be configured to show the number pad first by default. I have this one use case, playing farkle mostly, where I like to split screen excel and an image of the rules, and because excel is open split screen the keyboard always opens to letters. It drives me nuts that I cannot force a keyboard to open to a number pad.
I've got three soft keyboards enabled on my phone, to choose between as needed.
Unexpected Keyboard is my default; it's a perfectly cromulent basic keyboard, that makes all the punctuation, ctrl/fn/esc available for comfy shell work.
When I need to type in non-ascii characters like accented letters, I have AnySoft available. And pwsafe has a soft keyboard in it to let me avoid passing my (exceedingly hard to type, long random) passwords through the clipboard.
I used to have Hacker's Keyboard in the mix, but Unexpected Keyboard has made it unnecessary.