The ease of use as well as the ability to customize it to fit my needs. It took me about 3 days to learn most everything I need to know for what I do. I have since created other applications in the same area that are much more complex. But I still haven't found an application like this one anywhere else. It would be nice if you could export to Excel or save a copy of the data before you close out so you can go back into it later. This is also very helpful when you're at a job site and don't want to bring up the program on your phone. Tracking jobs and customer information. As well as tracking invoices.