Three weeks following the previous seed, Apple has released iOS 7 beta 4 for iPhone, iPad, and iPod touch to registered developers. The release follows Apple’s Developer Portal going back online late last week following an 8 day outage. The new seed is available via the over-the-air Software Update function in the iOS Settings app.

The previous beta release brought several user-facing changes (video here), including a sharper system-wide font, interface enhancements to Safari, Calendar, App Store, and Music, as well as improvements to Home screen folder transparency, a functional built-in dictionary tool, and more improvements to Siri’s more realistic voices.

A download link and claims regarding this new beta emerged earlier this morning. As the public release of iOS 7 approaches this fall, it is likely that beta 4 will continue providing interface and stability enhancements.

If you find anything new in this beta, you can let us know at tips@9to5mac.com. We will keep updating this post with a running change log of findings (below):

Lock screen is no longer confusing:

– Call button in Phone dialer is tweaked:

– Phone answer buttons tweaked:

Spotlight:

HDR in camera re-located:

– You can now swipe between panels in Notification Center

– Tweaks to image download in Mail.app:

– Safari graphics tweaks:

Tweaked filters UI (and added for some older iPhone models):

Search bar in Reminders:

– Readers reporting minor keyboard tweaks

– Improved back buttons in setup:

– New AirPlay icons:

– Slight UI tweak to Newsstand:

– Shuffle all songs is back:

– Improved animations and transparency in folders on the Home screen.

– New iPad resolution changing button while running iPhone-only apps:

– Completed uploads notifications:

–  Siri Q/A

– Choose a sound for AirDrop alerts:

– Faster calibration in Compass.

– iPad multitasking now supports unlimited apps. Previous betas capped it at 10 open apps.

– Video of snappier animations

http://www.youtube.com/watch?v=AlL9l44eUsk