You've packed your passport, your adaptor, a few pairs of underpants and maybe a good book. What else do you need? Once upon a time you'd have needed local maps, printed itineraries, timetables, guidebooks and much more besides. Not anymore.

Our trusty smartphones are already indispensable in daily life, and but with a bit of pre-planning you can turn your phone into a travel agent and companion that does let it do all the hard work for you – here are the ways you can do so.

Booking entire trips on your phone has never been easier

The free Google Trips app launched in mid-September and we already don't know how we lived without it. Available on both Android and iPhone, the app's main feature is that it automatically pulls your reservation details – flights, hotels, car bookings and more – from your Gmail account and collates everything in one place. Times, addresses, contacts and booking references are all saved and arranged neatly together, along with automatic suggestions for day trips, restaurants and local attractions – including offline maps and directions to help you get there. You can bookmark plans, from dinner reservations to musical performances, and have the details pop up at the relevant (local) time. (If you don't use Gmail, TripIt works in a similar way and is a very viable alternative. Simply forward all your booking emails to TripIt's email ID and you’ll find all the information you might need in the app.)

The cheapest flights can be nabbed with minimal effort

Trips is not Google's only travel app. Google Flights is a relatively underrated tool that's packed with powerful functionality when it comes to looking for the best deals on flights – as long as you know what to look for. Try searching by "flexible dates" and open the price graph tab to source the cheapest dates to travel to your destination, with real-time prices rather than estimates on display. Try this trick in reverse by plugging in your dates and selecting "discover destinations" to look up the cheapest places to travel during that period, filtered by region. Another handy tool is the ability to save itineraries with a single click. You can then set daily price alerts (the Google Now app is a neat tool for this), or simply check back regularly to make sure you snap up the best deal as soon as it’s available.

You'll never forget things anymore

PackPoint (available on Android and iPhone) is a personal suitcase butler that gives users a list of essential items to pack before departing. To hone the list and make it more useful, simply create a trip profile detailing the type, destination and length of your stay. PackPoint is then able to give you a customised list of the stuff you'll need, including an assessment of the type of clothes to bring based on the current weather forecast. (Spoiler alert, a raincoat is a popular suggestion for the UK.) There are also a variety of premium features available, such as TripIt integration.

No more arguing about those bill splits

You may have used Splitwise or Tipulator in local restaurants with a group of friends, but they can feel even handier on holiday. Such apps are a great way to split and track group expenses and can prevent many headaches and awkward arguments – particularly when bills come with confusing post-purchase tips and taxes (we're looking at you, USA). Splittr is similar in concept, but is specifically designed for the traveller. It can quickly generate a specific post-trip report that you can email around to the group, ensuring no-one is able to duck out. And if you're visiting multiple countries on a single trip Splittr is even more essential – it's able to mix currencies and work offline.

Lost in Translation no more

It's always good fun to learn a few words in a new language when you travel. Duolingo is a free and immensely popular language-learning tool, with an engaging interface that is one of the very best ways to pick up some of the local lingo before you set off. However, Google Translate is seemingly trying to eschew the need for that altogether with its impressive live translate feature. Simply point your camera at a word (on a menu or road sign, for example) and it will instantly translate the word for you in real time, displaying it in situ on your display.

Getting lost (except on purpose) is a thing of the past

Local map apps continue to get better. Citymapper is proving increasingly indispensible for many big European and US cities, and also covers Hong Kong, Seoul, Sydney, Melbourne and Tokyo. It's generally superior to Google Maps, and with its real-time traffic updates and detailed public transit guides, you'll wonder how you ever got anywhere without it. Naver Map is a great one to try if you’re heading to Korea as Google Maps reportedly doesn't work as well there (heads up: you have to type addresses in Korean), and Baidu Map will help considerably for travel in China (though again, you'd have to understand Chinese characters to do so.)

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