message in ios and android device

public/views/paperWallet.html

@@ -36,6 +36,7 @@
         </label>
         <input id="passphrase" type="password" name="passphrase" placeholder="Passphrase" ng-model="passphrase">
       </div>
+      <p ng-show="paperWallet.message" translate class="size-14 text-gray">{{paperWallet.message}}</p>
       <div ng-show="paperWallet.balance">
         <label for="totalBalance">
           <h2 translate>Funds founds: {{paperWallet.balance}} BTC</h2>

src/js/controllers/paperWallet.js

@@ -3,6 +3,7 @@ angular.module('copayApp.controllers').controller('paperWalletController',
     self = this;
     var fc = profileService.focusedClient;
     var rawTx;
+    if (isCordova) self.message = "Decrypting a paper wallet could take around 5 minutes on this device. please be patient and keep the app open."
 
     self.onQrCodeScanned = function(data) {
       $scope.privateKey = data;
@@ -83,4 +84,4 @@ angular.module('copayApp.controllers').controller('paperWalletController',
         rawtx: rawTx
       });
     };
-  });
+  });