Feature Ideas

Set optional start and end dates on tasks to make planning easier.

For example: "Repeat after completion" "Repeat X days, weeks, months... after previous item is checked off". For bills to send or training items it makes sense to create a new tasks when previous is completed with a parametre.

Allow users to manage labels (e.g., deleting, renaming) to give them functional use.

Enable users to quickly search for content across lists and tasks.

Enable users to add priority levels to tasks; e.g., low, medium, high.

Enable Windows users to manage lists and tasks with a dedicated desktop app.

Create lists that would basically just be a named saved filter in the sidebar. Setup features could include labels, statuses, dates, assignment, etc. Really filtration by any combination of properties to generate the contents of the list.

Enable Apple Watch users to add, view, and complete tasks on the go.

Another highly useful feature - voice input into Siri right into the inbox. Omnifocus has the best implementation, Things isn't bad. Here is how it should work: use your iPhone to say something like: "Remind me to go to the Drycleaners tomorrow" A task immediately goes right into your inbox: "Go to Drycleaners" with a due date of tomorrow.

Attach files directly from Google Drive using Google Drive’s attachment popup API instead of finder. Then, when opening a Google Drive link from Superlist, have it open in a new tab on Chrome.

Enable users to assign multiple people to a task to enable collaboration.

It would be great if a recurring (main-)task (e.g. weekly) would be displayed in the day view without the recurring subtasks within it (which are e.g. weekly, bi-weekly or monthly) appearing as a separate task in the day view. In my case, it is a weekly recurring task with 3 subtasks that recur weekly, monthly and every 90 days. On the date when they are all due, I would have 4 tasks in the day view, unnecessarily displayed separately.

Add the support of multiple languages for web, mobile and app versions

This isn't a 100% deal breaker but the ability to have tasks linked to a location and have them pop up a notification/reminder when I leave/arrive at a given location would be nice.

Enable Linux users to manage lists and tasks with a dedicated desktop app