After installing TweakSP and activating the Installation Feature on the Central Administration Web Application:

You will get a new tab in Central Administration for TweakSP. The new tab contains quick-links to the new administration and layout pages that make up TweakSP:

There haven't been too many visible changes from v0.0.0.2 to v0.0.0.3 (most of the work was behind the scenes; focusing on installation, localization, etc) but one of my favorite new features is in the Administration Hierarchy section:

First of all, let me say that yes, I know this page is ugly. It will be getting a huge makeover in v0.0.0.4. The biggest change in this release is that I added context menus for the site collections:
My favorite option is the script context to PowerShell which opens up a new window displaying the PowerShell script you'd want to run to get that Site Collection's context:
My plan is to introduce similar functionality in many different TweakSP pages (View Extended Site Content, View All Features, etc) so developers and administrators that are new to PowerShell have somewhere to get started.
A new page that I've added is the View All Features page:

This page gives you a quick view of all the features installed in your farm, grouped by their feature scope. This is another candidate for context menus - I just need to figure out what the actions will be ;-)
Another key feature I added was an Admin Settings page/infrastructure:

Currently there is only one configuration option (turning database tweaks on/off) but as TweakSP grows, I see this area growing quite a bit.
If Database Functionality is enabled you will be able to see the early version of the Activated Features page:

Unfortunately there isn't anything in the object model that tells you WHERE a feature is activated. That information is stored in your content databases though. This page will eventually grow to:
- display friendly names/URLs
- support filtering by Feature Id (where is feature ABC activated)
- support deactivating/uninstalling
That's all for now - definitely let me know if there's something you'd like to see in future releases, if you're experiencing any issues, or if you would like to help out!