Here are a few useful tools for calculations and such...

SWR Loss Calculator - Good to see how much signal is getting out with your given match/mismatch.

4nec2 - Free antenna modeling software. I use it and I love it.

Morse code call sign weight - tells you how "weighty" or long your call sign is in Morse code. If you are looking for a new vanity call and want something that is easy to send, run it through this first.

Koch Method Morse Code Trainer (G4FON) - Very good software for learning Morse code.

Beam Antenna Calculator - Use to generate lengths for a beam antenna.

If you have any tools you would like to share to have posted hear, leave a comment below and might add it!