I developed something similiar but for the Android API, it goes together with an app, but it is also a Java Read-Eval-Print Loop where the code is executed on the device. It's in beta phase.
https://runondroid.com
Oh very cool. I've used sl4a for this, but it would be very nice to have access to the original Java API for experimenting with new features for an actual native Android application. I look forward to trying it out.