The previous beta of SwiftKey Flow hasn't allowed you to 'flow' in all text fields, but it looks like this has been fixed up in the latest betas to hit the SwiftKey website.

The new beta looks much more refined and sports less features this time around, where it includes easier corrections, new languages, a new theme and more. The full changelog is quite hefty:

Changes in this version:

• Predictions (and Flow) now on in most places (exceptions: email fields, passwords, anywhere where the app doesn't behave itself with SK, fields offering their own corrections on Android versions before 2.2)
• Easier corrections - just tap on the word and SwiftKey will offer you 3 possibilities
• New languages: Thai, Vietnamese, Bosnian, Albanian, Javan, Sundanese (plus those added in 3.1)
• Features from SwiftKey 3.1: Berry theme, split layout in landscape on phones, Armenian, Azerbaijani, Georgian, Hindi, Hinglish, Irish, Macedonian, Spanish (Latin America) and Tagalog
• New layouts for Hindi and Russian
• Ukrainian landscape layout fixed
• Backspacing on to the final word of a multi word prediction (Flow through space) will now give better alternatives
• Typing style now inferred rather than a setting
• Long press delete accelerates after the first word

Bugs fixed:

• Flowing off shift no longer triggers a change in shift state
• Flow no longer gets stuck when you flow off the bottom of a page
• Quick period working after single letter words
• Arrow key repeats
• Learning when sending messages or tabbing between fields with the enter key fixed
• Azeri capital i behavior corrected
• Estonian will now predict words containing the estonian o
• Fixed force close on Beta predictions
• Flow trace no longer left behind after flowing
• Mounting an SD card will turn predictions off only if SwiftKey language packs are stored on that SD card
• Keyclick sounds no longer doubled
• Haptic duration made consistent with flow on and off