I have an Android app called "QuickPic". It's a little quirky but it allows you to transfer files to your tablet or other Android devices via wifi. Also bnut is a great place to document your progress.
There may be a thread with a similar subject where you may find more ideas. Good luck!
I just use Google Photos. You can add info to each photo, organise into folders for each tree, etc. You can also enhance and crop the photos. Works well on mobile devices with the app.
I've an Apple app called "BonsaiDo" (I think it's also for Android). It's very simple. I can save my bonsai and any kind of works.
You can find it here bonsaido.net