WhenWorks is available in both Free and Pro versions. Both versions provide the following features:
The only difference between the Free and Pro versions is:
WhenWorks Pro is sold on the App Store as an auto-renewable subscription via in-app purchase.
To purchase a Pro subscription, launch WhenWorks, tap Settings in the upper left corner, then tap Upgrade to WhenWorks Pro.
In the following screen, tap one of the buttons to purchase either a Yearly or Monthly subscription.
Your WhenWorks Pro subscription will be charged to your credit card through your iTunes account. Your subscription will automatically renew (every month or every year, depending on the term or your subscription) unless cancelled at least 24 hours before the end of the current period.