You can use Octo, your own emulator, someone else's emulator, or real hardware, if you have some sitting around. You can even have a go at hand-assembling your code on paper if you think it would be fun!
I do recommend that at some point you test your program on Octo, even if you don't use it for development. It has a number of "quirks mode" flags that can accommodate the differences between most CHIP-8 implementations, and it provides an easy way to share your end results here on Itch.io.
For what it's worth, MyChip8 emulator, which I wrote in C++ using Qt OpenGL graphics for the display is relatively new. I use Octo to compile and MyChip8 to run. The source code and building instructions for the emulator is on GitHub at: https://github.com/TomSwan/mychip8
