Trips Pro (also available lite)

$10.49
iPhone, i Pad and iPod TouchManage information on all your Flights, Car Rentals, Hotels/Hostels, Trains, Buses and Cruises. Check flight status, integration with Trip It, interactive maps, Dining, events and meetings.
Also access program online from your PC.

If you want a travel planner that incorporates everything in one place, this is it! Plan out your day-to-day doings with this great app. If your a regular traveler or planning a large holiday, this app is priceless. I have just finished putting in 40 days worth of traveling into my i Pad version of this app, it’s simple to use and easy to understand, information is presented in a creative way.

RailTeam

Free
iPhone (can be use on i Pad)Plans trips by entering arrival/departure stations, plan trip using GPS at current location, live international and domestic timetables, fully integrated maps, detailed trip planner, save favourites, real-time information on delays and platform changes and view station maps.This app has extremely detail information about trains, stations, platforms, what type of seating/sleeping is on board, route your trips. One of the best free apps out there.

I regularly use this app to source train times.

XE Currency

Free
iPhone and i PadLive currency rates and charts, calculate prices and simultaneously monitor up to 10 currencies.This app speaks for itself, even more handy when traveling thru countries not on the Euro.
Take precautions when traveling on holidays. Always remember to call and confirm your flight in advance. For example, if You fly to Egypt, You can open this page Egyptian Visa for more information.
Rick Steves’ Audio Europe
Free
iPhone (can also be used on i Pad)Downloads and stores audio files on your device, no WiFi or mobile connection required to listen, handy maps (PDF) that complement self-guided tours, new tracks always being added, keep checking for new downloads.A vast library of Rick Steves’ audio content organised into geographic-specific playlists. It’s a free guidebook on your iPhone/i Pad, plug and play with your own personal tour guide.

Booking

Free
iPhone and i PadResearch and book hostels, hotels, apartments, castles and camps. Over 8 million properties worldwide. Use maps to find the right hotel in the right location. Add to passbook to easily store your bookings.I booked all my Europe accommodation through this website.
Noel_Bauza / Pixabay

Triposo

Free
iPhone and i PadSelect the countries you plan to visit from the Triposo Travel Guide, it will download immediately. Once downloaded the guide will work offline. Detailed maps including sights, a list of restaurants and nightlife options.A free tour guide in your pocket, packed full of useful information on all major cities in Europe and the world.

Citymaps2go (available in lite)

$1.99
iPhone and i PadOffline maps, 6,700 interactive maps, millions of POI, 500,00 Wikipedia abstracts of sites and attractions, GPS find your own location and nearby searches, unlimited download of maps.

Skype

Free
iPhone and i PadCall other friends on Skype for free, instant messaging, photo sharing, call mobiles and landlines.

Lonely Planet Travel Guides, Phasebooks and Maps

Free (but the guides cost around $4.49 to purchase)
iPhone (can also be used on i Pad)Start your journey with the world’s favourite travel guides and phrasebooks, all available in one free app.