I see that there is a method to "verify reciept" from my server to Apple's api but if I'm reading the documentation correctly, this can only be instantiated via request from the app which talks to itunes, then sends a transaction object to my server. My server then takes that transaction object and verifies with itunes, then returns a success back to the app.
My concern is that if my user starts a long term auto-renewing subscription on the iPad (i.e. pays monthly), they may access their data via my website, etc and if they don't open the iPad for a long period (but keep using my service via web or other device) I can't verify they are current with payment until they reopen the app on their iPad.
Is there an exposed api that my server can call intermittently to find the status of an ongoing subscription?