I did this earlier today for a client's notes only:
This is what I did for a client today. I followed mementothegreat's instructions but I wanted to expand them to help those looking for notes only. I installed Imazing trial, opened a itunes backup inside Imazing (recent backup after ios 11 update worked fine). Went to "File System" then right clicked on AppDomain-com.itcomapps.sk and saved it to a folder on my computer, in the root of C called INFO. It then created a file called Smart Safe 1.8.imazingapp. I used 7-zip to extract that file and now I had a folder called Smart Safe 1.8 that had all of the files. I went to C:\info\Smart Safe 1.8\Container\Library\Application Support\Data and found the main database file called notes.sqlite. I then downloaded DB Browser for SQLite from http://sqlitebrowser.org/. After installing the program, I opened it and selected open database and selected C:\info\Smart Safe 1.8\Container\Library\Application Support\Data\notes.sqlite. Once it loaded the database, I clicked on the Browse Data tab and found all of the clients notes in the ZBODY column. I clicked on each ZBODY and it shows me the notes that he entered in the upper right. At this point he can copy and paste the notes out in to other programs. He didn't have any saved photos/files so I am unable to speak to that although there may be a folder that has them all in there if you had some. I suggest poking around if you are missing anything else. This worked for me and he is a very happy man now, regaining 132 entries that he had. I hope it works for you.
** I showed the exact directory names for how I setup my restore folder, yours will vary if you do it differently. If this is confusing, get a PC tech and he/she should be able to use these instructions to assist.