What's a good technique for tracking if a user has an IAP Subscription

We are trying to implement a membership/subscription model, and we are running into some surprising challenges. Would love to get people’s input on our design and our challenges. Also, we are trying to find a solution that would work across iOS and Google Play Android.

Design
In Google Play, rather than using their subscription IAP product, which restricts us to just 1 month and 12 months options with unchangeable prices, we want to use the managed IAP products. So, we’ll define products that represent 1-, 3-, 12- months. In iOS, we are thinking of using the non-renewable subscription IAP product. Using this design, if the person were to re-install our app, or install our app on another device, we want to be able to honor their subscription and give them access.

Challenge
The biggest challenge is how would the user “restore” a subscription, and for the system to know when that 12-month subscription was originally purchased, so that we can properly calculate the expiration date. Some of the things we have tried:

1 - When doing a restore, we tried using the event.transaction.date and event.transaction.originalDate. But, we noticed that the date is a formatted string (“Aug 5, 2012 12:00:00 …”), so we can’t do math on it to calculate expiration. Question to Corona Guys - can you expose the time in Epoch Time?

2 - We then tried to record the time of each purchase using Parse.com. But the problem with this approach is, we can’t correlate a purchase from DeviceID123 to DeviceID456 without the user giving us an email address or some other identifying information that we can record into Parse.com that can be used for querying later. We are concerned that this would turn-off users.

So, at this point, we are completely stuck. We really appreciate any suggestions/help!!!

[import]uid: 41124 topic_id: 31156 reply_id: 331156[/import]

We are stuck in the same boat. Our Subscription is for a 7 day auto renewable subscription. [import]uid: 34105 topic_id: 31156 reply_id: 124612[/import]

I understand the reluctance to ask for an email address, but if I’m joining a membership “anything” I wouldn’t blink at being asked to identify myself. That’s completely reasonable. Especially if I want to share my membership across devices, identifying myself on each device has to happen.

Just tell people, “…if you want to be able to restore your data at some point or use your membership on multiple devices, please enter your email address here so we know who you are.” Or something like that.

Jay [import]uid: 9440 topic_id: 31156 reply_id: 124642[/import]

We are stuck in the same boat. Our Subscription is for a 7 day auto renewable subscription. [import]uid: 34105 topic_id: 31156 reply_id: 124612[/import]

I understand the reluctance to ask for an email address, but if I’m joining a membership “anything” I wouldn’t blink at being asked to identify myself. That’s completely reasonable. Especially if I want to share my membership across devices, identifying myself on each device has to happen.

Just tell people, “…if you want to be able to restore your data at some point or use your membership on multiple devices, please enter your email address here so we know who you are.” Or something like that.

Jay [import]uid: 9440 topic_id: 31156 reply_id: 124642[/import]