There are many more cool (and mostely free) plugins on smutard's website. Direct link to products page: http://www.smustard.com/products/
A couple of sketchup plugins that I have found very useful.
- Group by Texture: http://www.smustard.com/script/GroupByTexture I have found it isn't perfect if your model has many components/Groups, but just explode your model completely and then run it from the plugin menu. Boom, instantly grouped by material and ready for export. Just watch out for the "default" texture group. I am finding that if anything is left at default texture, you can import into TPS but when you try to use the *.tpsscn, TPS will stop working. So I hide all the groups but the default group, figure out what I need to fix (apply texture or eliminate a unseen/hidden face or texture was applied to back side). Once I fix the default material items, I unhide everything, explode it completely and rerun the plugin. Poof, ready for export.
- Reverse Faces: http://www.smustard.com/script/ReverseFaces. Very handy when I have a bunch of back faces showing. Please note: This plug in is operated from the tools menu (not the plugin menu). Click tools then "left click reverse face tool". It's active until you select another tool so don't random click around with it.
- Clean up 3: http://extensions.sketchup.com/en/content/cleanup%C2%B3 I have been using Cleanup on many models that I get from the 3D warehouse on sketchup and most need significant work to be able to use them in TPS, especially the nicer/detailed models. Lots of options and some are pretty aggressive, so best to read about them a little online before messing with those. My advice is to always save a copy before running cleanup.
A note on the nice batch processor above mentioned by Abletudu (thank you): You don't need it, but it can be handy when you have several models to export. First time I used it, I made the mistake of running it on a folder where I keep all my models.....ahem....oops.....it exported everything in the folder: 50+ models. No harm done as I just deleted the ones that I didn't need but it took a while but I wondered why it took a long time and flashed up every model I have on the screen. I should have read the instructions before diving in. <shrug>
Some of this is probably old hat to those who aren't new, but for those (like me) just learning, the help in this thread has been very valuable. Thank you all. Hope my contributions are found useful.