Type: Memory Editing Software
Cheat Engine is an open source tool designed to help you with modifying single player games running under window so you can make them harder or easier depending on your preference(e.g: Find that 100hp is too easy, try playing a game with a max of 1 HP), but also contains other usefull tools to help debugging games and even normal applications.
It comes with a memory scanner to quickly scan for variables used within a game and allow you to change them, but it also comes with a debugger, disassembler, assembler, speedhack, trainer maker, direct 3D manipulation tools, system inspection tools and more.
Tutorial for Flash Games
1. Download, install. Use Firefox if using for flash games(Chrome tends to open up multiple processes and I don't use IE).
2. Once you are done, open up Firefox and go to the game you want to hack. For this tutorial, I have chosen Bloons Tower 3(note: this will not work with some games; some need to be swf decompiled, apparently).
3. Open up CE 5.6.
4. Click the button that has the image of a PC w/ a search icon(being choob friendly). Search for the process "firefox.exe". Other games have different processes(MW2 = iw4sp(mp).exe).
5. Return to the game.
6. Select map, blah blah blah etc.
7. Now, the money amount should be at 650
8. Return to CE
9. Input 650 in the value box, then click First Scan
At this point you will notice that many results come about. That's why you..
10. Return to the game. Buy a monkey

. You should have less money.
11. Return to CE. Input the new amount in the value box. Click "next scan"
Note: First Scan scans the entire game. Next scan simply re-scans the same addresses. This eliminates old addresses that have no possibility of "controlling" the amount you want to change.
12. You should have one address left. Double click it. It will appear in the lower area.
At this point, you can control/edit several features. For now, I would recommend only toying with the value(which matters most anyway). Also, you can edit the Description, or things will get confusing after a while.
13. Double click the value. A box should pop up like the following;

14. Input the amount you would like, then click okay
15. Double click the description. A box should pop up like the following;

16. Input the name. For ex: I would put "money" or "exp", so I would know what the address changes in the future.
Note: Some addresses require you to "freeze" them, or they will change back. Click the Frozen box.
In Bloons Towers 3, you must buy another monkey to refresh the game so that your money changes. Same with any other change. This applies only to flash games.
Extra Notes:
-For games like MW2, simply look at your exp amount, and search for the address. It should be the first one, in fact.
-Some flash games require you to decompile the swf to find values

-You don't have to search for exact values. For HP that is not determined(like CoDs), search for decreased value
[YOUTUBE]zGplfENmswY[/YOUTUBE]
Video Includes footage of Making a Trainer
To make a trainer, click Advanced Options>Save(it's a button)>Create New Trainer. Open New Trainer allows you to modify an old trainer you've built.
Note: To prevent leeching, click the following button. People can also open your trainer and pretend it's theirs.
Please Thank and Rep. Took a while.
Have fun,