Apple - Is there an app that will track "Time since last full charge" on OS X?

Everything you need is provided with OS X.

For graphical details and an overview, open Activity Monitor and the energy tab lists the time you have been on your current power source:

In my case, it was showing 5 hours on AC power, so I disconnected the charger to show that the battery is just starting up. The graph on the right will give you a nice history if you go between multiple charge/drain events over the last 12 hours.

For details, use the pmset command in terminal app:

pmset -g log

Since that log is verbose, you might start with filtering the messages about Using

pmset -g log | grep Using

You could try MiniBatteryLogger

It helped me troubleshoot my battery issues. I'm not sure it will do exactly what you asked for but when you have it running (on battery or power adapter):

MiniBatteryLogger monitors your laptop’s battery, traces the graph of charge and amperage over time, compares your battery with other users, logs relevant power events and alerts you with Growl notifications.

And right now it's even free:

We are undergoing some changes and cannot issue licenses. … In the meantime, you can use this evaluation key:

Register MiniBatteryLogger

I found Battery Logger by Ananta Sjartuni does exactly what I want.