Promising features for Freelancers who want to keep tracko of projecst

I am a translator, and I get new projects almost on a daily basis.
Often, towards the and of the month, I find that it takes me forever to track projects, amounts, when people need to pay me, when they have actually paid, and what Tax is on a project.
I think that Reno could become my favourite app, if some features could be added. The most important ones for me are a calculator, a start- and a delivery date, and also a payment due, payment received feature. Ideally, I would be able to have a list of products / services, but tat isn´t so important. I´d pay money for that kind of app, as it would make my life a lot easier. Still, among the once I looked at, it is the one that fits best, and if it gets developed a bit further, it might be a super-tool for freelancers, handymen, and everyone who just needs something to keep track of multiple small jobs. I give it a 4, as they told me they are developing it furher...

Milow2000 about Project Reno, v1.1.2