Ask HN: Cloud-based RT logging for mobile apps?

Are there any services out there that allow centralized logging for apps installed by end-users as well as servers?

We have an iPad app which people use for hours on end and that we provide customer support for.

When diagnosing a problem a user is encountering, having access to a log of what the user is doing in real-time would be incredibly helpful. We have server-side logs that we'd like to aggregate centrally, but the interaction logging we do on our iPad app provides far more detail.

It seems that the cloud logging services I've looked at (Papertrail, Loggly, New Relic) are all meant for servers that you register manually and/or are priced by the server which would be prohibitively expensive.

What do people on HN use?