icon or button design for Thwam

Thwam

We are developing Thwam, a search engine for the iPad.

We need seven different icons/buttons to use for controlling various aspects of our app. Users will tap these icons to perform different actions. The icons should have no writing, just an image that gives a good indication of the icon's function. They will appear on white (#FFFFFF) and light grey (#d7d8dd) backgrounds.

The icons are:

Block - Allows user to block a search result from appearing again
Drill Down/Deep Dive - Conduct a URL specific search
Share - Social sharing
Bookmark/Save - Bookmark a site
Highlight - Highlights search terms on a page
Refresh - refreshes the browser
Comment - User can make a comment

The icons should contrast well against a light background but not be overly dark. There will be full color photos and graphics on the page and the icons should not detract from these graphic elements. Lighter, muted colors should be considered but we are open to suggestions. Designs should be flat, not three dimensional.

All icons should have a similar color scheme but do not necessarily have to be the exact same colors. They should have a common shape outline such as circles rounded rectangle, square, rectangle, etc. They should be simple and not too complicated. The final icons will display on an iPad screen at a roughly 25x15px size (normal) and 45x45px (retina).

We'll need the PSD source files in vector format for the winning design.