This is my favorite one yet, very user friendly. I only wish it was a bit more configurable. Ideally I'd be able to set up something like:

  3 of 4: A B C D
  - OR -
    2 of 3: E F G
    - AND -
    1 of 1: H

Though there's something to be said for the simplicity of the current design.

There's an implementation packaged up for most Linux distros: http://point-at-infinity.org/ssss

There are several browser-based versions which can be used online or downloaded to use offline.

https://bs.parity.io/ -- http://passguardian.com/ -- https://iancoleman.io/shamir/