Before updating to 5.2 the unit should be updated to 5.1.39.first. The 5.2.x software can be used on almost all Quadro2x units. The exception to this is for older Quadro2x models that have only 32MB of NAND flash memory. Beginning with 5.1.38 software the size of NAND flash memory is also displayed within the Quadro GUI under System/Status/HW Status page. Only units that indicate 64MB of “NAND Flash” size can install 5.2.x. For more details see the 5.2 release notes.
For opening the access for iQall go to Internet Uplink/Filtering Rules and click on Add. Select HTTP or HTTPS (if you want secure connection) and Action - Allowed. Enter the IP address or your iPhone and press Save. If you don't know the IP address or iPhone - put 0.0.0.0/0 in IP mask and save but then everybody from the Internet may have access to your unit and therefore you need to have a strong admin password.