I stopped working on PlainText for iOS, WriteRoom for iOS and TaskPaper for iOS a number of years ago. The short story is they didn't make enough money to pay for development. Hog Bay Software had to shrink back to just me, and my focus has been on TaskPaper for macOS and (now in progress) WriteRoom for macOS.
Unfortunately iOS 11 is incompatible with these apps. When you update they will remain on your iOS device, but they will fail to launch.
To recover your files:
First in each of these apps you could store your files:
- Directly on the device.
- Synced to iCloud
- Synced to Dropbox
The recover method is different depending on where you were storing your documents.
Recover from device
If you were storing your files directly on device you can recover by connecting to your computer. Opening iTunes. Selecting your iOS device. Selecting the "File Sharing" browser. Choosing the app whose files you want to browse. And then you should see a list of plain text documents that you can drag and drop onto your computer desktop.
Recovering from Dropbox
If you've been syncing your documents to Dropbox you can access your files by going to https://www.dropbox.com and going into the /Apps folder and looking for a folder named after the app (WriteRoom/FoldingText/etc) that you are looking for files from.
Recovering from iCloud
Unfortunately while these apps all sync to iCloud they don't mark the documents as visible on iCloud Drive. So you can't just browse them from iCloud.com or the macOS finder. Instead you need to:
- User Terminal.app to go to
- Use the
ls -all command to list all content (including hidden files) in that folder.
- Find the folder with the name of the app you are looking to recover. For example my PlainText documents were stored in a hidden folder named
64A5CLJP5W~com~hogbaysoftware~PlainText. Go into that folder and then type
open ./ to open that folder into a Finder window... you can then browse and do what you want with the documents.
Alternative method is to use third party iOS filesystem browser app
There are a number of third party app that allow you to browse the filesystem of your iOS device. I just tried iExplorer as was able to see both my stored only on device files and also my iCloud files.