One of my couchsurfers used an app called journi - I downloaded it and can follow along with the rest of their Canada trip. I haven't tried it myself - I may with this years holiday just to see how it works. I really do miss that you could use TravelPod offline - not sure if you can with journi or not.
After losing travelpod, I tried TravelArk but just couldn't get into it. So I'm using one called Traveller's Point, and I copied all my TP entries over. I don't find it great for photos tho, so I haven't uploaded many...and they don't have an app to the best of my knowledge.
When we went on holiday last year, I just made notes everyday on my Notes app, then used that after getting home to do up our travel. I honestly just do it for myself anyways (I can't imagine anyone looks at it) - so I can go back and look at what we did on what day, or where we may have eaten, any issues that arose (funny or not so funny).
Quick edit - I just tried journi with my wifi off and it seems to work still...but not 100% sure on that. Also, the last few years, I've gotten into doing up a photobook for each holiday - I was going to physically scrapbook but never got very far. This way, I can do the photos and do blurbs for each day of what we did, etc. And they take up so much less room than having 200 photos printed and put in an album, or never looking at the photos because they are all on the computer. We let family and friends look at the books, and even some couchsurfers who have expressed interest in looking at them. Journi will do photobooks up...I use Photobook Canada- there is always a groupon for them, I like the quality, and once you send them to print, they arrive within week-10 days. You can do hardcover, softcover, layflat, landscape, portrait, square, various sizes - and even if you didn't want to put a lot of photos, you could still use it as a journal of your travels!