Agile Tortoise's Tally for iPhone (US$0.99) is a no-look, incremental counter app that's simple and useful. The whole screen becomes a button, so you can pay attention to your data source, not the iPhone. There are modest collection adjustment and export options, plus handy gesture support. Here's our look at Tally for iPhone.
There aren't a huge number of people who need an incremental counter app, but I can think of at least one example. Years ago, I was a special education teacher at a residential school. We took lots of data with our students, like the number of times a behavior is performed within a given time period. Back then, we made tally marks on a piece of paper with a pen. While low-tech and simple, it meant looking away from the student to record an occurrence. Those brief seconds spent looking away could mean missed data points.
Tally lets you record data without looking at the phone. Once launched, the entire screen becomes a button. Tap it anywhere to record a data point. An audible "click" confirms a successful tap. If you make a mistake, swipe down to remove a data point.
You can optionally name a group of data (or a "tally" as the app calls it) and start a new collection whenever you like. Simply swipe to the left to reveal the list of tallys or start anew.
By default, Tally's data increases incrementally by one. You can change that, too. Swipe to the right to set the initial value, or starting point, and step value. For example, count by twos, threes, fives, etc. You can also specify if Tally should record up or down and give your custom setting a name for re-use later.
Finally, you can send data to Drafts to take advantage of its myriad of export options.
Tally's simplicity is its strength and weakness. On one hand it couldn't be easier to use. If you can touch your iPhone's screen, you can record data. The fact that you can look elsewhere is a real plus. On the other hand, recording options are rather limited. As a special ed. teacher, I'd like options for percent of intervals, procedure duration and more.
Of course, Tally isn't meant for teachers specifically -- though many could benefit for it. Check out Tally now and get counting.