In a drastic move aimed to roll back the clock on what the developer says was a huge mistake, Realmac Software is making its popular, minimalist to-do list app Clear free for the first time. Realmac released a universal iPhone and iPad app called Clear+ last year, pulling the original version from the App Store. The episode highlights how the App Stores restrictions can cause headaches for developers in multiple ways — Clear+ existed in the first place because there is no way to offer upgrade pricing to existing users, meaning developers often have to choose between updating their software for free or charging everyone the same price for a new version of an app.