"is there an aid to help speak Spanish in the tu form?"
most of the time things are expressed formally in the translation engines. is there an engine that will help when speaking informally?
This is one of the things I love about Spanish, the 'defaults' are formal and respectful. I don't hear the usted form in conversation, but nearly always when there is a guest evangilist at church they will use the usted form. When you don't know someone, it's the right way to speak.
Unfortunately the usted form is what is mostly taught. I will finish all of Pimsleur this week and almost the entire course is in Usted form. I asked my mom, a pyschologist that sees almost entirely hispanic clientes, and speaks in Spanish all day....if she hears a lot of usted form in her daily life....she said she never hears it...that no one uses it ever and she doesn't know why it is so widely favored for teaching over the usted form. Maybe they are really worried that you offend somebody?