The day I needed to install anything on my phone for my mega-corp employer I went out and bought the cheapest Android phone I could find.

What was an interesting discovery was that PingID doesn't require a cellular data connection to work, so I was able to use the phone unregistered (so no network charge) and permanently in flight mode (to preserve the battery).

Even now after leaving that company I still haven't registered the phone or taken it off flight - I just connect to a personal wi-fi as necessary.