When you’re on a night out, sometimes it’s difficult to keep track of what you’ve had to drink - was it one, or two, or maybe even nine? As we all know, such questions become infinitely harder to answer as you imbibe more and more alcohol. Then, before you know it you’ve parked your car on its roof down some busy one way street in central London.

Granted, this is obviously a worst case scenario - but if you do ever worry about whether or not you’re fit to drive, then iDrinkSmart is a handy bit of kit to have around.

Before using the app you are required to input your weight (Kg), gender, and height. Additionally, one nice touch is that the app tells you what your height is in feet, which is useful for the less metrically-minded amongst us. For example, if you’re 5’10, then you need to enter 1.78 metres.

Obviously, the app cannot give you an empirical break down of the exact alcohol content of your blood, there are far too many variables, but as estimates go, it’s better than nothing, right?

There are four drinks options to choose from: Beer, Wine, Spirit and Mixers, and Spirits. Once you select one, say wine, you drag a cork across the screen from left to right until you find the correct quantity you have consumed. The measurements are very precise and come in litres, UK fluid ounces, and UK pints, which means you can always be very precise when inputting what you’ve had to drink.

However, it is quite fiddly to operate and the measurement reading is tiny, and is seriously hard to operate effectively after a few drinks. That said, you can pretty much track every drop you drink, so design flaws aside, it is actually quite useful. 

You can additionally set how much time has passed since you began drinking and how much you have eaten - although, this is done by pushing a burger, which comes in three sizes: Flat, medium-looking, and massive. As you’ve probably guessed, this isn’t the most accurate way to measure your food consumption, but again, it’s better than nothing...

Once you have all the information inputted, the app then calculates your blood alcohol content, and tells you whether or not you can drive via a traffic light, which is located on the right hand side of the screen - obviously, red means you’re getting a taxi home.

Whether you actually go out and put this app to the test is up to you. However, it’s probably worth noting that during testing we consumed five pints of lager, inputted the info, and were told four hours later that we could safely drive home... Now, we aren’t legal experts, but we were pretty sure this wasn’t right, particularly since we also felt a little drunk... But like we said, it’s up to you, and the app does have a disclaimer, so you won’t be able to sue if it costs you you’re license.

While there is an obvious point behind this app, it’s nowhere near as useful as it sounds.

Quite early on in the night we became very frustrated with its fiddly controls and Laissez-faire attitude towards drink-driving.

In short, this is a useful application for anyone who is interested in keeping a log of how much they actually drink over a specific period of time. However, like all BAC calculators on the market, it cannot give you an actual reading, merely a theoretical guess based on the very limited data you put in.