"RectLabel - One-time payment" is a paid up-front version and its price is $59.99.
It is fully feature equivalent with "RectLabel for object detection". If you want to test RectLabel please take advantage of the 1 month free trial in the standard "RectLabel for object detection" version.
"RectLabel for object detection" has Paid Subscriptions.
You can choose $2.99/month or $29.99/year payment.
They include 1 month free trial.
Paid Subscriptions are managed by Apple. See Apple Media Services Terms and Conditions for the appropriate terms and conditions for your country.
Payment will be charged to your Apple ID account after the 1 month free trial.
Subscription automatically renews unless it is canceled at least 24 hours before the end of the 1 month free trial.
Your account will be charged for renewal within 24 hours prior to the end of the 1 month free trial.
You can manage and cancel your subscriptions by going to your account settings on the App Store after purchase.
Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable.