When was the last time you cleaned – or even wiped – your phone screen? Yeah, we can't remember either. And when you think about how much time we spend handling our devices, that's pretty gross.Now, toilet users in Japan are being offered a second smaller roll of paper alongside normal toilet paper – designed specifically for cleaning smartphones and tablets, reported The Times Japan's Narita International Airport has installed the dispensers for rolls of paper, which are smaller versions of regular toilet paper, in 86 bathrooms in its arrivals terminal.Our phones can carry more bacteria than a toilet seat because we don't wash our hands enough, according to research conducted by consumer watchdog Which? in 2013. Germ levels on some devices were "hazardous", causing vomiting and diarrhoea.Another reason why they're so teeming with germs is our habit of taking our devices with us to the toilet to pass the time.In the Which? investigation, one iPad had 600 units of Staphylococcus aureus , a bacterium that causes food poisoning, while smartphone had 140 units, seven times the number found on a typical office toilet seat – which tends to be cleaned and wiped with anti-bacterial agents more regularly than our devices.Japanese toilets have a reputation for cleanliness. According to a survey by Japanese toilet manufacturer Toto Ltd. conducted last year, 93.6% of foreigners said Japanese public bathrooms are cleaner than those back home.If you've ever visited the country as a tourist, you may felt a bit confused the first time you used a public bathroom. Electric Washlets are ubiquitous and, with music, heated seats and an intimidating number of spray settings, using a Japanese loo can be an experience unlike any other.The smartphone toilet paper was created by a mobile phone operating company and will remain in place until 15th March next year.As well as helping users to keep their phones more hygienic, the paper also includes information in English about WiFi services and travel information in Japan.The lack of publicly available WiFi can also be a shock for travellers and is the "biggest issue" for foreign tourists travelling in the country, according to a survey by the Japan Tourism Agency in 2011.