iA Writer is file storage provider agnostic but we recommend iCloud for the best experience across most devices.
If you are already using Writer for iOS or Writer for Mac apps and have enabled iCloud, you’ll find a dedicated iA Writer folder in your iCloud Drive. To access this on a Windows device you can download and install iCloud for Windows.
Note that prior versions of iCloud for Windows suffer from a number of compatibility issues. Updating to the most recent version of iCloud for Windows before adding iCloud folders to Writer is highly recommended.
https://support.apple.com/HT204283
https://apps.microsoft.com/store/detail/icloud/9PKTQ5699M62
If you are experiencing a problem that our support section doesn’t solve please reach out to us. We take a break on the weekends (JST), but during weekdays we aim to reply within 1-2 business days.
iCloud 
iA Writer is file storage provider agnostic but we recommend iCloud for the best experience on Mac: Set Up iCloud iCloud is on by default, but you can check with the following steps: Open macOS System Settings Click on your name (Apple ID) → iCloud → iCloud Drive → Apps syncing to iCloud Drive Ensure
iA Writer is file storage provider agnostic but we recommend iCloud for the best experience on iPhone: Set up iCloud iCloud is on by default, but you can check with the following steps: Open iPhone Settings app Tap on your name (Apple ID) → iCloud → iCloud Drive → Apps syncing to iCloud Drive Ensure
iA Writer is file storage provider agnostic but we recommend iCloud for the best experience on iPad: Set up iCloud iCloud is on by default, but you can check with the following steps: Open iPad Settings app Tap on your name (Apple ID) → iCloud → iCloud Drive → Apps syncing to iCloud Drive Ensure
iA Writer is file storage provider agnostic but we recommend iCloud for the best experience across most devices. If you are already using Writer for iOS or Writer for Mac apps and have enabled iCloud, you’ll find a dedicated iA Writer folder in your iCloud Drive. To access this on a Windows device you can