It's main selling point is that it encrypts all your data (notes, pictures) with SHA-256 before storing it on your device. Give it a try (Disclosure - i am the developer in the team that published this app)
Reviews/feedback always welcome...
I don't really use it, but I use a to-do app constantly, and miss a tool to continue writing on my projects' Markdown files.
[1]: http://benthebodyguard.com/
