Since this tool is online based you don´t need any special requirements for your device. This online GTA 5 money generator is mobile optimized and should work well with most known devices. Yes, it is tested with different devices and browswers and should be bug-free. Some have said that the tool froze, but it helps to reload the page and all should be good again.
As for the game itself, it runs on multiple platforms like Playstation 3, Playstation 4, XBox 360 and XBox One. Since these platforms are straight-forwards, this game is optimized to run on them. A little different topic is the PC version, which should be released any minute now. It has quite demanding parameters your desktop/laptop must have. Below you can find system requirements for PC version. Don´t worry, I´m sure we can add this money hack to PC version when it comes out. You can also get more information regarding specifications from Rockstar Games.