If you haven’t got the three following apps, you need them. As a writer/oversharer, I am completely addicted to these 3 the most. They are all free!
Quickpic: No ads, no messed up loading, and it lets you share to Messenger, Facebook, Dropbox, Cloud (and a bunch of others I don’t use myself), and allows the use of my #2 fav app Send Anywhere. The best program I have ever seen for saving photos. My Samsung provided one, for my tablet, sucked royally.
Send Anywhere. Send a photo or file directly to the person you want simply by having them open the same app on their device (while you have yours open) and select which type you are Send or Receive, then have the person receiving type in the code generated on your device. BOOM! Songs, Photos, or documents shared. I use this when my Kindle freaks out and deletes my MP3 files. (I can download my songs back onto my device from Dropbox and less cursing happens)
Writer: This one perfect for writing to my blog. It is the ONLY one I have found that does easy peasy copy/paste without making html changes to the text. Life Saver when I want to copy my posts onto my Kindle, or vise-versa. I also love that I can type notes and ideas while at work or on the bus. Woot!