Download this app if: you want to manage and edit your blog.
Squarespace Manager allows you to enjoy the power of Squarespace in your hand. You can post and edit blog entries, upload pictures on the fly, save drafts, preview your updates, and access your website statistics. The latest version supports all Squarespace accounts.
For power users, Squarespace...
Blogtastic — If you use this service to blog with, then you'll likely find this app is invaluable for posting and editing entries on the fly.