Ok, kind of annoying using the free version. You can zoom in, but it pops back after you take your fingers back off the screen. That's not so bad, but then it pops a notification in your face about upgrading to stay zoomed, every time. There are other annoyingly ugly reminders scattered around.
Esentialy the intrusive remiders to upgrade make this more of a demo than a lite version of the app. It lookes very usable, even well done otherwise. Take a look and decide if is worth the $2.99 price for the in app primium upgrade. You won't want to use the free version for long.