A: Please find my comments inline,

1. How long has the site been in business?
#Acadle is just a year old, but this is our second product from the company. We are in business from last 6 years and we are working with multiple Fortune 500 companies with our first product. You can see more details about us on website (about us section)

2. Is it possible to sell individual courses? For example have 10 in total and have 2 free but if people want to get any other they need to pay for each one
#Yes, you can integrate payment gateway via Plugnpaid, Pabbly Connect, Integrately, API, Coupons etc. We are also launching our own native stripe integration in a few days, almost done

3. Is it possible to schedule recurring payments?
#We do not have the feature, but you can do with integrating plugnpaid

4. Do you have plans to add audio only to the lessons?
#Yes

5. What does gamification include exactly?
#Option for you give points, give badges, show who is best learner, with the help of leaderboard etc,