If you are looking for a quick and minimal software or an app to edit your photos on the phone for free, then you must check out Adobe Photoshop Express Its available for your android phones as well as iphone on the appstore. You can edit the photos on the fly and share them instantly with your friends and family. Having used it for a while I believe its better than the native app available on the phone (I am using Samsung Galaxy S) and also one of the quick and simple photo editing app on the Android platform. Photoshop Express comes with the options such as: filters and effects enhancments, borders, apart from the regular features like crop, straighten, rotate, flip, and adjust color. Other notable features include

• Backing/posting photos at Photoshop.com (needs an account)
• Instant sharing on Facebook and Twitter
• Automatically sync pictures taken from mobile to photoshop.com account for accessing anywhere.
• Works on Android 1.5 or later

Pros:

• Automatically loads all your photos
• Simple and easy to use
• Just slide the finger to control the levels of modification
• Backup options with Photoshop.com account

Cons:

• Minimal features
• Limited sharing options  (FB, Twitpic & Photoshop.com)
• Limited filters and effects