Money is in. How do I keep track of it? I will not promote.

My startup got funded, we have enough to survive the next 18 to 24 months, but how do I keep track of our expenses (past and projections) to make sure we will indeed survive at least 18 months? I've seen a few interesting products on product hunt but they seem to be in closed beta and I need something right now. Preferably something that integrates with our bank accounts and provides an easy interface: we are not CFOs and we are focusing on building our product.