From the ASE wiki:
"ASE lets you develop on the device itself using high-level scripting languages to try out your idea..."
What would prevent ASE from being used to develop a full Android app?
I don't actually know but I suppose you can make a full android app in ASE.
As the author of the article on SISC, I looked int ASE. The emphasis, as far as I can see, on the ASE is on 'scripting', running scripts to access certain parts of the android os. Which parts of the OS depends on the interfaces the ASE projects implements for the respective scripting languages to connect to. So far, I don't think the ASE project is focusing too much on the interactive elements (in android speak, 'Activities') of Android, those elements that users/developers think of as part of the 'app'. So, at the moment, ASE isn't really about building apps, but allowing scripting functionality to apps. Using JRuby or in this case SISC Scheme outside of the ASE environment could lead to full Android apps. (Hopefully)