I've used Unexpected Keyboard and FlorisBoard and I'd say that they're great introductory FOSS apps for most users (users inexperienced to sudden changes)
Unexpected Keyboard uses Nix in their codebase :D
Thumb-Key is maintained by dessalines whom is a Lemmy dev
Florisboard is starting to convert their codebase to Rust,
ah unfortunately I had to recently take down a post here that recommended HeliBoard, - as that project is in violation of OpenBoard's GPL-3.0 license
For some unknown reason the developers of HeliBoard decided to multi-license with Apache-2.0 and CC-BY-SA-4.0 - as I wasn't able to find any information that they received explicit consent from all members of OpenBoard about relicensing/multi-licensing
Hence I can't recommend anyone using that keyboard app until further information is disclosed - afaik multi-licensing GPL-3.0 is only possible with other specific licenses such as AGPL-3.0
just to double-check I searched online and found this: license-compatibility > Likewise, CC BY-SA 4.0 explicitly permits relicensing modified versions to GNU GPL version 3, but GPL version 3 does not permit relicensing to CC BY-SA. This issue should never arise for software code; Creative Commons says its licenses are not meant for code, and says that the license to use for code is the GNU GPL. But there are other kinds of works, such as hardware designs or game art, where you might have occasion to merge material released under CC-BY-SA with material released under the GNU GPL. This can be done through CC BY-SA's explicit relicensing permission.
> Unfortunately, CC BY-SA 4.0 does not permit relicensing to future GPL versions. What you should do, when you relicense material under CC BY-SA 4.0 to the GPL, is specify yourself as a license version proxy to indicate whether future GPL versions have been authorized for that material. If someday there is a GPL version 4 and Creative Commons decides to allow relicensing from CC BY-SA to GPL version 4, you as proxy will be able to retroactively authorize use of that relicensed material under GPL version 4. (Alternatively, you can ask the authors of that material to give permission right away.)
You have to load the library for that separately, but it makes it very easy to do.
As far as features that gboard doesn't have, the main one for heliboard is that you can edit the secondary characters. That's pretty damn nice. For one, it means you can set it up to mirror the secondary layout of any keyboard you're used to, reducing any swtich caused learning curve. For another, if you want to roll your own entirely, it's super easy to do, even easier than multilingo, which is the only other editable keyboard I'm aware of.
Gripes? Honestly, only that it isn't a copy kid Swype, my preferred keyboard. It can get close, but it isn't exactly the same. It'll r be what I switch to if I ever have to give up swype.
I just started using Heliboard yesterday. It doesn't offer its own swipe typing library. But you can give it the library file from GBoard (link on their github) and it'll use that to enable it.
For gestures/swipe-typing I do know that all 3 have that feature
unfortunately I can't provide reviews on it as I still tap to type, haven't had time to retrain unfortunately
For Florisboard's features I really like their sea of options for customizability:
it gives me Arch Linux vibes as it give you plenty to fiddle around with like:
hinted symbols/number row, built-in Incognito mode, undo&redo, built-in dev tool toggles, customizations backup&restore, etc
gripes wise is wanting remap keys but this is such an insignificant gripe considering all the features they've implemented
I'd imagine that this is a potential feature down the far future
For Unexpected Keyboard, the features it provided was actually unexpected:
like I didn't expect to get a Ctrl, Fn, ESC button, like wtf that's pretty awesome!
it also has a single button arrow d-pad!
essentially this has all the keys on a desktop keyboard
gripes wise I wish there was a language indicator for when I'm switching between dvorak, qwerty, and Korean
this is also a very small nitpick that will probably get implemented later on
I haven't used Thumb-Keys but I've seen good reviews about it so it's worth a shot as well 👍