Here are (mostly) free travel apps that will help you traveling.
It takes all your reservation emails - organizes them for you - and makes them available in 1 place.
Traveling together? Just pay; enter payment and who paid; and let it tell you what you each may owe.
Help for what to tip, e.g. when in the US; and gives you the percentage amount.
Turn your photo into a post card and have it mailed - only $1.99
No work: puts together daily 1 second video clips into a trip video!