Steer clear!
I downloaded this app approximately five years ago. I paid the one time fee of six bucks because the app was able to manage my fire department schedule (PTO, kelly days etc). Now the developer wants everyone to pay an annual subscription fee,both those who are downloading it for the first time and those whove been loyal users for years. The developer wants YOU to pay to make up for his poor business model. If he is willing to charge folks a second time for the app they ALREADY OWN, whats to prevent him from doing it again, to you. Sounds like theft to me. My advise is to stop using this app if you currently are and dont download it if you havent yet or be prepared to be disappointed. Create a calendar in Google maps and import it for FREE
Napahlm about
Spark - Shift Calendar