Q:

Stripe subscription add-on's & features

Right now I have 3 types of subscription at my site:

Starter (10$)
Plus (15$)
Premium (19$)

Also I have few add-on's which user can add to his subscription, e.g.:
Subscription : plus

+feature 1(+10 $)
+feature 2(+10 $)

Total = 15$ + 10$ + 10$ = 35$.
User should be able add/remove features during his billing period or switch to another plan.
Can you guys tell me how should I manage those features using Stripe.

A:

On Jan 30, 2017 Stripe released this functionality by supporting multiple plans for a single subscription. 
More information 

Unlike our multiple subscriptions on a customer capability, which
  generates an invoice for each subscription, putting multiple plans
  into a single subscription results in a single invoice each billing
  period that combines every subscription. Only a single payment for
  that invoice is required, reducing your costs and the number of
  charges your customer sees.

A:

Stripe doesn't natively support add-ons. There are a number of third party tools that add this feature on top of Stripe, which can be useful if you're dealing with complicated up and downgrades with prorations.
Using just Stripe, standard practice would be to create a subscription with the plan (Starter, Plus, Premium), and then listen for the invoice.created webhook each month to add the necessary add-ons.

