I was using My Safe Notes which I liked BUT it wasnt updated for iOS 10 and crashed constantly. I found this as a replacement and it does the job that I need it to do. No matter how good an app works some will downgrade it for minor things such as ability to change colors or font or language or ...
This isnt fancy but it does exactly as advertised - it protects your NOTES with a password. It isnt a word processor nor is it suitable for desktop publishing, but it doesnt claim to be - it is simply a utility for securing your notes.
Keep your phone backed up and your data will be safely backed up too.
It is well worth 5 stars.