For journaling, how about Day One? I believe it's iOS only, but I use that for my personal travel journal while out on the road and it's pretty awesome.

Photos I take on my mobile devices are stored in Apple Photos and Google Photos (I have both an iOS and Android phone).

Pre-trip notes are stored and organized in Evernote for easy reference while I'm at my destination.

Google maps (duh)

I downloaded an app called Everplaces yesterday that looks interesting - it allows you to "bookmark" interesting places you find as you're traveling (with pics, text, maps). But it's a bit rough around the edges though so I hope it evolves into something more substantial.

Anyone else? I love cool travel apps as well, but there aren't too many really good ones out there.