6,214 votesWill commented
Personally, I think you just need to sure up the calendar integration. And give users the ability to make custom smart lists like the default "Today" smart list. Give me the ability to make a "Next Week" or "This month" smart list.
7,765 votesWill commented
There are three types of reminders Wunderlist needs BADLY:
1. Repeating every X units. Every 3 days or every 6 months or every 2 years. Allow the user to pick the interval and the time unit.
2. Repeating every Xth day of a month: Every 3rd Tuesday of the Month or every 5th Monday.
3. Custom repeat for a given week: Some tasks are business days only: MTWThF every week. Or they only happen on days a user has class like MWF. Give the user the ability to select which days a which a task that happens multiple times a week happens.
Essentially all the options that Outlook or Google Calendar offers you. I think your users will find it weird that you don't have parody with the calendar apps you integrate with.