I would like to create a shopify payment app like "recharge" for taking recurring payments along with one time product purchase payments.
Customers on the shopify store should be able to make a one-time purchase or purchase the same product in a set interval...say 1 month or 3 months or 12 months etc....
The product then renews every month or 3 months etc charging the customer monthly or whatever is set for the shop owner
Please take a look at cratejoy as well.
I would much prefer for a similar project as ReCharge.