Cheat Engine

[Robotex]

so a basic injectable dll should be like this

[Grytolle]

..then you must find whatever function shows text in the game and call it using the correct parameters! =D

[Bepetemish]

a good thing to do is making a dll with hax.
Then you add as extra your name, you can find the adresses with CE searching for text, or use a debugger.

Now when they start the game and it needs to load, most games got plane text in the upper left en below right corner. This can be changed to your name.

Now everyone knows this dll is made by you, i do this because i can't put my name anywhere on the dll like you do with a trainer