If you're training (e.g. at a gym) or testing something in a lab as part of your work then you'll be familiar with the concept of an interval timer, an application to keep track of the number of repeats of something and to audibly and visually let you know when the allotted time period for each repeat is up. Yes, it's something of a niche use case, but if this sounds like something you could make use of then this new Symbian application, Interval Timer, is well worth a look - it's slick and immaculately programmed.

Here's Interval Timer in action:

You start by picking an interval mode (which will depend on what you're doing, for example) and tapping in the appropriate parameter - in this case the number of times to repeat the interval.

Then the interval itself and whether you want to stay in the portrait, small-fonted view or whether (for example if you're exercising) you want to use the landscape, large-fonted view.

By default there's a visual and audible countdown and then you're into the intervals - note that you'd usually have the 'lock' function engaged, so that you couldn't tap the pause or stop icons by mistake and thus mess up the current interval. 'Slide to unlock' is only within Interval Timer, it doesn't lock the whole phone, which is actually a neat compromise...

The lock function also works in the landscape view, shown here. The large fonts work well when the phone is (for example) several metres from you.

There's a lengthy help/summary screen, though the app is intuitive to use, I doubt anyone would need to read most of it.

Impressively, all application functions are customisable, so you can tailor Interval Timer to be exactly what you need it to be. 

Note the 'Preset' numbers at the top of the screen throughout - you can save up to five sets of intervals (e.g. for different exercises or tests) and then recall them at will. Note that you can also have multiple timers, i.e. several going at once, which may help in a 'lab' use case.

Implemented neatly in Qt,  Interval Timer is programmed to use a dark theme, which is great for saving power. The only glitch was that the app took a while to exit after use, leaving the user with a blank screen - I'm sure the developer can do something about this, if only to put up a 'Saving...' message?

You can buy Interval Timer in the Nokia Store for £1 or grab a 'Lite' version (with less functions) for free.