If you have a lot of data and frequently use Smart Lists with potentially complex date filtering etc, the app may feel sluggish at times on certain hardwares. Although we try our best to squeeze performance out of existing / older hardware as best as possible in each of our updates, here are two ways you can improve performance for sure:
1. Open 2Do > Settings > Appearance > Auto-delete Completed Tasks and set a range such as 3 months or more. This way, older completed tasks that you don’t need to keep track of will be removed from your device, resulting in a smaller, faster database.
2. Open 2Do > Settings > Notifications > List Counts and turn list counters off. These are the overdue / due today counts that show against each list on the main screen. List counts, when turned on, can use a significant amount of processing power for smart lists (or the Focus Lists). On older hardware or on larger databases, this can become a bottleneck. Turning this off will immediately speed up your workflows in most cases.
Starting with iOS v3.6.1 you can in fact turn off List Counts only for Smart Lists from Settings > Notifications > List Counts, whilst keeping them for everything else.