You can add the Todo Cloud Widget on iOS by doing the following:
- Ensure you've first installed the latest version of Todo Cloud from the App Store.
- Swipe down from the Home screen, Lock screen, then swipe right from your Notification Centre.
- Scroll to the bottom and tap Edit.
- Tap
beside Todo Cloud to enable it, you can the reorder it by tapping and holding 
next to it and drag it in the order you want. - To finish, tap Done.