NOTE: If you have a habit of force quitting apps or use 3rd party apps that force quit apps (by ’cleaning memory’), 2Do will NOT sync in the background! Apps that are force quit manually, do not automatically launch in the background by design. iOS does this to prevent apps that have been manually killed to relaunch again without user intervention. This is a bad habit any way, as iOS is able to do a better job managing memory for you automatically any way.

Background App Refresh, a new battery preservation feature of iOS 7+, allows iOS to periodically request several apps to connect to the internet and download new data all at the same time. This one-shot refresh mechanism has the potential to extend battery life as it allows iOS to decide which apps take part of this ’refresh’ spree. In the past, apps were able to run in the background for as long as they required. This resulted in poor battery life and so apps can no longer run indefinitely at will.

2Do is set to automatically refresh between 10 to 20 minutes. This means that iOS may ask 2Do to perform sync in the background at least 10 minutes after being closed. At times if the battery is low, for example, or if 2Do took longer than a certain time limit the last time, iOS may decide to skip or postpone this call the next time it decided to group several apps together to participate in a collective refresh. We’ve also noticed that if you’re connected to WiFi, iOS may frequently initiate sync in the background, but if you’re not, it may not sync for several hours - rigorously trying to save you from excessively using cellular data.  If you’re making a lot of changes regularly and there’s a lot of data to sync, iOS may at times postpone this call for several hours (as we’ve seen in some of our tests). For example, one of our users had around 1,000 tasks and he frequently was deferring, deleting and adding a lot of tasks, all of which added to the total time it took to sync these changes over an apparently poor network connection. This behavior caused iOS to postpone background refresh for 2Do several times during the day, thus resulting in what it seemed ’sync isn’t working in the background’ situation.

If you find yourself with tasks that aren’t frequently updated in the background, it may in fact be better to turn Background App Refresh OFF for 2Do and rely on in-app sync. There is sadly no direct control over this behavior and we’ve seen from different reports that the time between sync can vary greatly. iOS seems to apply a number of heuristics in order to determine if it’s beneficial to save the battery vs. frequently allow apps to connect to the network and sync.