Creating your own module is really easy if you have existing Android development experience and an application with a content provider.
The simplest modules can be built in less than 2 hours (e.g. bookmarks, and half of that time was trying to figure out the thumbnails) with more advanced ones requiring a lot more time.
How it works
Grab the Tabr API
Create a content provider with a matcher for the instance, record and data paths
Implement methods to fetch data into a Matrix cursor that can be returned from the provider to Tabr
Write a very simple service (abstract class provided) so Tabr can fetch information about your module
Write an Action receiver for Tabr to return click actions to your module
Setup your manifest with the content provider, service and broadcast receiver so Tabr can find, access and send actions to your module.
Compile, install to device and run!
I will release the API and the code for contacts and bookmarks soon so you can use them as a template (or at least see how easy it is!).
If you would like early access to the API please contact me.