Your bank should have to support the apple watch in their apps... I have 2 banks here in Canada that supports the apple watch... I can check my balance on my wrist without any password or anything, real convenient
I love the citi app, I could use glances to check my balance(much faster after 1.0.1 update) and use the app to see recent transactions(up to 5). The best feature is it sends realtime transaction notifications, which is very very nice.