Super Productivity is a free open-source task management app, available on both mobile and desktop. It has 50k+ users on Android and a 4.8 star rating on Google Play. It supports multiple sync backends, including "file-based" options which use standard cloud storage solutions such as OneDrive or Nextcloud. The user can optionally enable end-to-end encryption (E2EE) for these file-based syncs, where all of their sensitive task data is stored in encrypted form.
When users were setting up one of these file-based sync options, they were only able to set up E2EE after they set up the syncing. This meant that if a user already had sensitive task data, this data would need to be uploaded in plaintext before they could enable E2EE.
I contacted the Super Productivity maintainers about this issue in an existing private communication channel I had with them, advising that allowing users to enable E2EE during the initial sync setup for file-based providers would be a significant privacy improvement. The maintainers agreed, and updated Super Productivity accordingly.
The changes made can be found here: https://github.com/super-productivity/super-productivity/pull/8709