Physically supplied user information is used to first verify the identity of a user before an app is supplied to a user device. Hardware identifiers of the user device are reviewed to determine whether to allow or deny use of the app on the user device. Once the app is approved, a user request is received by the app which is forwarded to the provider. The provider approves or disapproves of the request based, in part, on whether data in the request matches data maintained by the provider. Such approval/disapproval is provided from the provider to a party responsible for satisfying the user request. In addition, the provider generates a one-time-use electronic signature using data from a sequencer and data from the request, and the one-time-use electronic signature can be supplied to a signature repository and/or added to legal documents.