PPSSPP and PPSSPP Gold have everything you'd want in a PSP emulator:
PPSSPP Gold also:
PPSSPP Gold is currently available for Android, Windows, macOS and iOS.
It is not currently available for Linux (or Steam Deck), for example.
More platforms are planned to be added in the future, but as these are by far the most popular four, they got done first.
Whether you own PPSSPP Gold for one of those platforms or not, feel free to use the free version on any platforms you have, as much as you want.
The payment provider uses the phone number in its algorithms to prevent credit card fraud. It is not actually used - you will not get calls from anyone and it's not stored.
If you have previously purchased PPSSPP Gold, you can request a license for Android, Windows and macOS.
If you have already bought PPSSPP Gold and want to support the development even more, you can always make another purchase for Windows/macOS or check it out on another platform.
Thank you for your repeated contribution!