What do you think of implementing a feature which prevents key-logger of getting your master-PW?
Unknown PCs (on which you will likely use your portable version of SPW) might be infected.
Thereby you risk getting your Master-PW stolen or do you really use the virtual-keyboard-method for a 15-digit-PW?
There are methods which prevent any keylogger to steal your PW upon typing.
Malware is able to monitor the computer's RAM in order to spy out passwords. Our new MemoryProtect function encrypts passwords before the system writes them on the RAM - even during the process when the password is entered. http://www.abelssoft.com/cryptbox.php
or http://www.abelssoft.com/cryptbox.php --> Memory Protect
for further ideas.