Well, that appears to be their problem. To get to the mobile app, they have to go through your on-line banking portal. In that portal is your agreement to which they agree. This is not an E-Sign issue, because a legal agreement between two parties does not fall into the E-Sign provision for document delivery which includes: "if a statute, regulation, or other rule of law requires that information relating to a transaction or transactions in or affecting interstate or foreign commerce be provided or made available to a consumer in writing". Whether they can access or print a copy through the mobile app really is up to you.
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