Naming products and Trademark checks

I'm an independent app developer. I picked a name for my app that I've been using through beta and just discovered that the name of my app is in name of another software company. If Foobar was my app name, they are Foobar software. We are in a different field altogether - I'm a consumer mac app, they're an IT / business integration tool set. It's a pretty generic word.

I performed a search at http://tess2.uspto.gov/ and of all the marks, the Goods and Services were always clearly different from my Goods and Services.

I'm not looking to file a trademark or hire a lawyer, or even be 100% sure, I just want to be sure I'm not obviously shooting myself in the foot.

What process do you go through when naming your app?