So you've decided to lose some weight. Or maybe you want to get your mental health in check.
There's an app for that, right? You bet there is.
In fact, there's now more than 250,000 fitness and health apps — dubbed "mHealth apps" — available for download.
But how effective are they and what proof is there they do what they claim?
According to a new study from researchers at Bond University — published in the scientific journal Nature — there is still very little evidence to show they actually work.
"Changing people's behaviour is hard and it certainly doesn't happen overnight. And apps alone can't do it," lead researcher Oyuka Byambasuren said.
The Bond University study didn't look at every app available. Instead, it started with a simple goal: to find an app that had enough evidence behind it that a doctor could happily prescribe it to patients.
They pored over hundreds of studies worldwide and managed to find only 23 comprehensive reports into the topic.
And the results of these were slightly disappointing.
"We found only a small fraction of the available mHealth apps had been tested and the body of evidence was of very low quality," the report stated.
"The overall evidence of effectiveness was of very low quality, which hinders the prescribability of those apps."
Among the apps examined were popular calorie trackers, which allowed users to monitor their diet and set weight loss goals.
The studies found over six months there were no significant weight loss between those using the apps and those who didn't.
Meanwhile, an app designed in Sweden to curb youth alcohol intake actually had the reverse effect, with young people who used it actually drinking more.
Ms Byambasuren said while apps could work for patients, they were more likely to be effective if they were used in conjunction with support from health specialists.
And she said her study only considered apps that had been subject to research, meaning there could be ones that worked but just hadn't been fully tested.
"We hope that the day we can confidently say 'an app a day keeps the doctor at bay' is near," she said.
"Until then when you hear someone suggest, 'there's an app for that!', ask, 'is there evidence for that?'."
How the apps can be helpful
Personal trainer Matt Leitinger said about a quarter of his clients used a fitness app alongside visiting the gym.
"My clients probably get the most out of the nutritional information apps," he said, adding that many would see, for the first time, just how many calories were in certain foods.
Mr Leitinger said the benefit came when they paired that information with learning how many calories they burned doing particular exercises.
But he said if people really wanted to lose weight, the formula was simple.
"Eating slightly less than your body burns per day in conjunction with regular exercise and you will lose weight and get fitter," he said.
KPMG performance coach Andrew May often advises clients on how best to deal with anxiety and mental health, and said he found some apps to be beneficial.
He often recommends apps that guide people through meditation, mindfulness and breathing exercises.
"Consistently using an app, even for only five or 10 minutes a day, can make a big difference to the ability to manage your state," he said.
But away from apps, Mr May offers a few tips for looking after mental health, including:
- Look after your body, as "healthy body equals a healthy mind"
- Build in regular breaks and get away from work
- Learn to relax
- Have fun and play, and don't lose that youthful playfulness
- Seek professional support if you need