I just uploaded my Android Dynamic Binary Instrumentation (DBI) framework. As I wrote before the framework is very simple. It supports hooking function entry points only. The source includes the shared library (.so) injector and the hooking/patching functionality. I also included one simple example instrument to sniff the UART communication between com.android.nfc and the NFC chip on a Galaxy Nexus.
I plan to further enhance this toolset and welcome everybody to submit patches. If there is a lot of interest I will move the source to a public archive like github.
The first release is available here: collin_android_dbi_v01.zip
To use this tool you need a Linux ARM gcc compiler such as included in the Android NDK.