[vimeo http://vimeo.com/44479512]

Checkmark is a new take on Apple’s Reminders app with additional features and a clean interface. It features the ability to create location- and time-based reminders like Apple’s solution, but it goes beyond what Apple’s implementation offers. For example, when creating a location-based reminder, you have the option of setting a delay before the notification appears. I especially like that, as I usually have a few things to do before getting to the tasks on my list, and Apple’s Reminders app sometimes reminds me way too early. Checkmark also offers time-based reminders, which work exactly as you would expect.

The area in which Checkmark really stands out is the interface. The app is much lighter than Apple’s version and feels a bit more responsive. It also has several different ways to view your to-do list, making it easy to find tasks specific to a location or time, or to see all of your tasks in a single list. Creating tasks for frequently used locations is quite a bit faster than the Reminders app, and you can set custom locations without having to add them to your own contact card in the address book (which is currently the only way to get a location to appear in the Reminders app).

After using the app for a little while, I found that I liked it. However, it did have some issues with recognizing my location. For example, I created three location-based reminders for my school, so I could remember to do some financial paperwork while I was there. After arriving, I walked around to a few offices before pulling out my phone and realizing Checkmark had not reminded me of any of those tasks. Curious, I went to the app and checked my school’s location. Sure enough, the app said I was nearby, but the geofence size that I set (the second-biggest available) was not big enough to cover the entire campus, and my current location was just barely outside of the area. I chose the largest geofence available and tried again. Even though the app showed me as being squarely in the middle of the geofence, it still failed to remind me of any of the three tasks. Many others have reported successes with the location-based reminders, though, so I decided to chalk up my experience to bad luck.

The geofencing feature also drains quite a bit of battery if left running for a while, but this is actually the fault of iOS itself and not Checkmark.

As for time-based reminders, they work exactly the way you would expect. Pick a date and time, add a title and description, and then wait until the time you set for a friendly reminder to do whatever it is you need.

Checkmark is an overall solid app with a great design and some very nice improvements on Apple’s to-do solution. It is available on the App Store now for the limited-time price of only 99 cents. If you are disappointed with Reminders in iOS 5, or just looking for something a bit more robust, this app is a no-brainer.