Please add subscription_start to the app_subscription object

Hey,

This is related to the app subscription object.

In the lack of a proper app usage and billing api where we app developers can query all current and past installs and subscriptions of our apps, and for those of us that didn’t implement app event webhooks from the get go, we have no way of knowing when an app subscription started.

We need this info for our support staff, for our CRM, for reports, and to present it to our subscribers within the app. Right now, our CRM is completely out of sync with our actual app subscriptions info.

Even if webhooks are implemented, if the processing of them fails, which it may some times, our CRM will become out of sync.

It is also best to present our users with up-to-date information returned within the app when the app is used, not on info received by webhooks.

What complicates stuff even more is the fact that webbooks will store the info in a CRM that is not easily accessible by the app itself and requires additional development, if we are to present this info to our users within the app.

For me, the app subscription object is incomplete without this information.