If you're looking at tools, there's also
System- Gives information about the CPU, battery, storage, etc. You can have it monitor and give history.
DiskUsage- Just shows you all your files in terms of size. See what's taking up a lot of room.
GPS Status- Compass and which satellites are being used.
Screen Grabber- Can do a screen shot without having to be rooted
Switch Pro Widget- Similar to the Power Control Widget, it allows you to customize to control up to 8 things from a list of 25
On Call End- When it's active, when you end a call you have a choice on what you do after. I have it set to Homescreen, rather than call log.
WiFi Analyzer- Gives the strength of the WiFi around.
WiFi Finder- Scans and shows on a map the nearest WiFi hotspots.
Battery Circle- Shows battery level in single digits. It sits in the notification bar so it doesn't take up any real estate on the homescreen. When you pull the bar down it shows voltage, temperature and how long unplugged.
Four new ones (for me) that I'm trying out are:
Open Signal- Shows the signal strength in percentage, as well as dBm. Has pointer and map to show where the cell tower is.
Smart Tools- Lots of different tools available for measuring, plum line, acoustics, etc. 4 suites for .99 cents each or all 4 for $2.50
GPS Esentials- Compass, hiking and other things with GPS
Phone Info- Easier to use than typing *#*#4636#*#*