Turn your smartphone into a professional car diagnostic tool with a $15-30 OBD2 adapter and free apps that read engine codes in seconds.

Free software on your phone or tablet lets you scan, create, edit, annotate and even sign digitized documents on the go.

However easy it is to digitally sign important documents, sometimes that won't suffice. When you just have to put your signature on a physical document and digitally upload it, and you don't have a ...