Popular to-do app Checkmark, usually priced $4.99, has gone free today on the App Store along with Units, a unit converter, and Ninja Slash, a 4.5 star rated game.
Checkmark: Checkmark is an excellent to-do app that takes the stock Reminders app one-step further. The app lets you set favourite locations, create reminders based on these locations including those that fire a specified time after you reach a certain location. It also lets you set time based reminders. You can download Checkmark from this link.
Units: Units is a unit converter for the iPhone that sadly isn’t updated for the iPhone 5. It however is a great app for older devices, and has a rating of 4 stars. The developer notes that version 2.0 is coming soon, and till then version 1 of the app will remain free. You can download Units from this link.
Ninja Slash: Ninja Slash is a Temple Run like runner game where you play the role of a ninja who runs through the streets, “slashing” zombies and avoiding obstacles. $0.99 usually, the game is a universal binary and can be downloaded from this link.