Absolute Noob here, apologies in advance for seemingly stupid questions.

I was just wondering, is the purchase price for the Harry's Laptimer app in the Appstore a one off price or a subscription? i.e. do I have to pay the asking price of £19.99 every year/month or do I pay it once and then have access to the software forevermore?
Also, i get that if you want to upgrade the app, from say the rookie version to the petrolhead version, then there is a fee associated. What i don't get is whether you have to pay for updates of the individual products? i.e. if I already own Petrolhead version V21, and subsequently V22 of the petrolhead product is released as an update, do I have to pay to get that update?
We've just bought an external GPS and a gopro 4 to take to track days with my old Man's MX5. Assuming I get the answers i'm expecting to the questions above we'll be buying harrys laptimer to record the data as it seems to be the most highly recommended product on the market!

Best
RW