Here is a time limited offer for iPhone, iPad and Apple watch users. You can get an application worth $15 for Free, the offer ends on 12th Jun, 2015. 2Do is released around three years before and is one of the best task management application available for the iOS users now.
You can sync your data with any of the following services, Dropbox, Reminders (CalDAV), Toodledo, Fruux (CalDAV), Calendar Server (CalDAV), ownCloud, SabreDAV or a 3rd party CalDAV Server of choice. It includes automatic backups too.
Create simple tasks, or checklists and projects with sub-tasks. Tasks can have notes, attachments and multiple alarms.
Set any task to repeat using a flexible set of options.
Assign multiple alerts
Create multiple lists to organize your tasks
Batch tagging, starring, marking tasks done and more
Task Sharing via AirDrop, iMessage and Email
Attach locations to tasks and get nearby alerts as you approach assigned locations
The application requires iOS 8.0 or higher, that means iPhone 4 will not be supported.
Read more about 2Do and get it for free from iTunes Store
Mac version of the software is also available. The price of that is $49.99 normally while you can grab that now with 50% off, that is for just $24.99.