Are there any distributed-computing Apps for Android? I've just found out about Boincoid: a port of the BOINC platform to the Android operating system as a platform for computing using volunteered resources (like SETI@home, Climateprediction.net, Rosetta@home, World Community Grid, etc). There isn't an actual app for Boincoid but just a zip package with a list of instructions dated from 2008.

Are there any other applications being developed for distributed-computing on Android?
I don't think so.  While you're ( they're ) on to something with the high amount of untapped CPU cycles accessible via Android ( and other mobile ) phones - the limiting factor tends to be that users don't want their batteries drained to compute fractals ( or something of the sort ).

If you were to create a service, however, that worked ONLY while the phones were charging, that would be a completely different matter.  However, doing so greatly reduces the time that would be available to tap those CPU cycles.

[Edit] - And further notes...

At one point I had investigated ( fairly heavily ) creating a distributed database system that would reside on mobile phones to support basic Apps that didn't want to rely on a REST service.  Ultimately, it came down to the lack of unlimited power that made it not worthwhile.  The goal still seems a bit of a holy grail in mobile application programming - create a distributed system that can take a service and database schema, and then add in a discovery and hash system to keep track of live nodes that had data.  Moving all of that information around could bog down a 3G connection - but a few years from now that won't be much of an issue I think.