hextool

HexTool is a simple calculator for hex, bin, oct and dec.

All values are editable so you can put a new hexdecimal value, decimal value, change single bits, put an ip address or ASCII chars. It will automatically calculate other fields for you.

The "<<" and ">>" is for shift operations in the current register.
The "flip" button performs an endian swap from the hexadecimal value.
The "not" button inverts the binary.
The "neg" button gives the inverse decimal value (signed mode).
The "small plus and minus" button increases or decreases the decimal value by one.
The "one or zero" button change the label from the binary starting with 1 or with 0.
The "clr" button clears the current register.

With the other buttons you can do bit calculations.
Therefore you can register your numbers in A and B and make logical and mathematical operations. The result is shown in register C.
You can change the register by pushing the radio buttons.
You can switch between signed and unsigned and you can set the bit size to 8,16 or 32bit.

https://talk.maemo.org/showthread.php?t=93299

http://sourceforge.net/projects/hextool/
http://harkin.org/hextool/index.html