Never allow any app to store your userids and passwords on any computing device.
Never do banking on a device that does not have strong security software.
Always delete your browser cache and all temp files as soon as you do anything that required a userid, password, or other credentials, and always immediately before AND after any important activity like online banking.
Only do online banking with banks that require a second login verification, such as a passcode message sent to another phone or other secure device.
If you are sloppy and careless about these things, nobody will be able (or want) to help you recover.
73, Ed