Disclosure: I helped with beta testing Tally. I also like Agile Tortoise. We all have our biases. Now you know mine.
Tally is a simple app for counting. It's as simple as counting should be. Start the app and it shows a zero count. Tap anywhere on the screen and it increments by one. But maybe you're a power-counter. Incrementing by one is for grade school. Slide right to left and a configuration panel opens.
Now we're playing with the pros. The configuration allows for setting starting values, step size and increment or decrement. If I title a counter, then I can save it and return to it any time.
Sliding left to right opens the list of previous counters. Slide down to reverse the current count by one. If it's an increment counter, it will deduct one step. If it is a decrement counter, it will add one step.
Sliding up from the bottom opens an action panel to send reset the count or send it to Drafts app.
Sure, it's a simple app. But counting should be simple. Agile Tortoise did a good job making something that worked perfectly for its intended use. The gestures and controls work well. By forgoing a "button" for counting, Tally can be used without looking. That's a feature.
Tally | iPhone | $1