There is also Atlas Right Track Software. Originally it was a purchase product, then they made it free, then they went back to purchase. Here is version #10, however as the comments say it is not as good as version 8 was. Version 8 has to be out there somewhere if you look long enough.I would like to build a layout in my garage. Is there a free app I can use to plan my layout on my desktop?
Yes. The only 3-rail HO that I know of is Marklin, so avoid that brand.I would like to use the HO scale, can I get the two rail with that?
Well, that depends on a lot of things like the bench work (table) that you put under it. Sounds like you are planning on putting down a flat surface, so generally the more framework the less thick. I think usually 3/8"-1/2" is used.What kind of plywood should I use for the table top?