No. Google has never released a desktop version. Any desktop software claiming to be Snapseed is a third-party clone that may require payment. Stick to the mobile app or the official web version.
As of the last few updates, Snapseed on the Google Play Store may list "In-app purchases" due to Google's updated policy on developer tools, but there are zero purchasable items inside the app. It remains entirely free. activate snapseed product key
Q: Can I use my Snapseed product key on multiple devices? A: Yes, you can use your product key on multiple devices, but you'll need to activate it on each device separately. activate snapseed product key