Left and right are available:
I've been a maker and board member of the French e-Nable association for a few years, and I've worked on several 3D printed devices intended for people missing part of a hand or an arm.
One of the most recent of these devices is the Kinetic hand, designed by Mat Bowtell, which is easy to print and assemble, with a smoother and more natural look than older devices such as the Phoenix Unlimbited.
These devices are muscle activated and require their user to still have a functional wrist or elbow. So far I've only seen one open source low cost motor activated 3D printed device, the Exii Hackberry. It's a great device, but I found it somehow uneasy to print and assemble, it's still a bit expensive, and I thought more recent electronic components would allow going further.
Which is why in 2023 I started to work on this project to combine both new hand design, and recent electronic microcontroller to drive the servomotors. I've investigated several solutions and here is the most promising one.
You can connect your Android phone to it over bluetooth and voice control it (in english and french for now)
The cost is estimated around $60.
This is still very much a Work In Progress:
Please note: I might not be able to keep the files here up to date at all times. I's better to check the Git repo below. If you are not familiar with Github just check the release page and download the latest firmware binary, Android APK and the zipped source that will contain the 3D files.
Github repo for the whole project including electronics, firmware and android app:
https://github.com/reivaxy/kinetix
Assembling instructions: https://github.com/reivaxy/kinetix/wiki (WIP)