Google is currently in the process of replacing the Google Checkout merchant centre with the new Google Wallet. Some users have already received this update and are reporting that Appmonger is no longer working for them due to the changes.
Unfortunately we do not currently have access to the new Google Wallet merchant centre and are therefore not yet able to investigate what changes are necessary to get Appmonger to work with the new site. At the very least it appears that it will require changes to authentication and support for the new sales report format.
Until we are transitioned to the new service, which could take several days or more, this work cannot start. In the meantime we have temporarily removed Appmonger from the Google Play store to avoid selling to users for whom it will not work.