This is shameless self promotion by mailing list lurker/looking for testers, but knowing that penti has audience here, I suspect my tool might also find some interest and even be useful.
https://play.google.com/apps/testing/morphles.CarrotKeys It is another input method that takes no screen space, and I'd say is a bit more traditional than Penti chorded keyboard, you basically dial in keys using thumbs. Each cell on the initial dial kinda represents "column of desktop keys". There are two sides for dials, for whats pressed using/left right hand on regular keyboard. And additionally, less systematic access to "non main area keys" (Fx, Del, home, arrows etc) via double tap for dial. I hope at least someone will like it/find it useful. Note: seems this initial release has an error left in, where after you enable input method, it will be crashing in the applications unless you first go to CarrotKeys settings (which you'll likely want to tune in for your liking, though I think names of options are not super descriptive currently. So I'll comment most important ones here: help radius - is percentage of screen size for displayed help circles. outer radius - is "active area" on screen for covering the help circle, this allows scaling motions with respect to help circles, so even though help circle can be half screen, the area where you move your fingers/thumbs can be minuscule (thus sensitive/fast/ blocking less screen with fingers). Note/disclosure: I also plan and advanced version (that would be paid), that will have ability to customize mappings, so that you could add all kinds of things like for example mapping to input something like "(cdr " with single dial. Mapping though happens via text file without any fancy interface.
