Momondo is an alternative to apps such as Kayak. While finding the cheapest flights can be pot luck, Momondo has a unique graph that shows you prices at any period, so you can scan across with your finger to find the cheapest times. Similarly, if you are looking to book a hotel, the interactive map allows you to draw a ring around any area for a list of hotels and prices. Momondo also allows you to sync favourites with any device.