On-screen. Very cool, thanks for the hint - the problem is that I don't want that keyboard for all the other apps. Can I pin a specific keyboard to a specific app (i.e. Hacker's keyboard to sshdroid + XSDL, and Google Keyboard to the rest)?
I'm not sure how well this works on newer versions of Android (probably not at all), but you used to be able to use a Tasker application context and the Secure Settings System+ module to automatically switch the IME depending on what application was active.