This is the Europe thread, but perhaps it could be adapted to track sightings of especially lovely French girls. That could become addictive as well.

I put all my stuff (documents, etc) in Google Drive, because I can look at it offline.

http://www.rome2rio.com/

It will get you there by car, bus, train or plane.
app for iphone also

google drive works offline?

Rome2 rio app
You can put in 2 cities or 2 local addresses and it will tell you how to get there by trains,buses ,taxi etc or how far to walk if local .
Also around me .It tells you where banks,restaurants,supermarkets ,stores etc that are nearby.

Bookmark

A 2012 thread that won't die.

Because the info is still relevant

For driving:

Mappy
Here

Tripit for all itinerary w all reservations.

Dropbox for all my documents so need not use email.

The flashlight, alarm, already listed multiple times.

Bookmarking

TripAdvisor

Pretty-Streets

bookmarking

Is there a particular currency converter app any of you prefer? The Google Play store has many of them for Android. All of them seem to have equal satisfaction scores...but I'm always leery of random reviews.

buckeyevet--I use the xe.com app. A couple months ago our trip was 3 countries so it was nice to have the app and not have to keep remembering what the currency conversion was.

mms,

Thank you. App is downloaded and very informative!

I really want to create my own custom city guide app for my homeland

Yes, maybe it's the best app

Trip It hands down. I upgraded to Pro level which has been very helpful. Trip It Pro notifies us of airline schexule changes, cancellations before the airlines do. I keep all my past trips on it too, helpful when teying to fecall which car rental company we used, etc.

Hey, just wanted to introduce the new travel app Kaktus that connects tourists and locals - it's based on a shared economy, everyone can join. It launched in 44 cities in 30 countries worldwide. You can browse locals from the given cities, filter them based on the common interests, check their profiles & book the tour with them. Whole tour process is handled in the app, up to the payment. You can check it at thekaktusapp.com