After a month of use, I find the basic functionality of this app works perfectly. That is, clocking in and out. But that's all you can do.
At the very least, it needs a notes field, to notate when you clock in too late by accident. The website already supports this. I think this is a sign of lazy developers, because I see there hasn't been a version update in over a year.
Other than that, please fill my iPhone 5 screen; I hate when apps are letterboxed. And it would be nice to see some new features, for example a nice way to view my current and past timesheets without going to Safari.