Can I open my databases on Android, Windows or other devices? Can I use Strongbox?

Yes, you can open your databases on many different platforms. Depending on whether your database is in Password Safe or KeePass format, you can find a client that is compatible.

For the Password Safe format, here is a link to a short list of compatible clients, you can probably find many more with a search for ‘Password Safe client for [insert platform here]’.

https://pwsafe.org/relatedprojects.shtml

For databases in one of the KeePass formats you can find many clients here:

https://en.wikipedia.org/wiki/KeePass#Unofficial_KeePass_derivatives

Strongbox is only available for iOS and Mac at the moment but there are many clients for many other platforms available as you can see from the above.