This is exactly the app Ive always wanted for logging my check card transactions on the go. The interface is designed so that the app is ready to accept a new transaction as soon as it is launched, and it had the fewest amount of clicks to get a transaction logged that Ive ever seen (perfect when youre at a crowded grocery store checkout). The feature set is nice and trim- all of the core useful features without any unnecessary ones. My only suggestions would be to flip the 10-key number entry to match a traditional layout (with the smallest numbers on the bottom) and to place the "subtract" button to the right of the add button, since it is most likely going to be used more frequently.
USER237772 about Account Book - Money Manager