Sync not working automatically
Have paid for premium version to get auto sync amongst other features, and... it doesn't work properly.
On two or three occasions I have noticed that there are todo items still listed as incomplete when they have been completed.
This has happened in Firefox, Web App, and Android.
What gives? Doesn't your server send a push update on changes?
Additionally I set a reminder on a task which is supposed to send a notification to the Android app - this didn't materialise.