No.1 is a simple arithmetic exercises of the mind. Make the result of expressions to "1", by changing the operators "+, -, ~, ". Those operators can be changed by clicking.
For example:
@2+7+9+4=1
should be changed to
@2~7-9-4=1
One game can be done in 1, 2 minutes so it can be a good small pastime.
iPhone version is also available.