My wife was super awesome and gifted me the GrovePi with a Raspberry Pi Model A+ for Christmas! However, the docs do not say anything about GrovePI and Raspberry Pi Model A+ being compatible.
Is the Grove Pi compatible with the Raspberry Pi model A+?
Indeed congratulations on your awesome wife and her great taste in gifts.
Karan is right: the A+ will work fine. You’ll just need to make sure that the back corners line up with the GrovePi pin header. Pins 1+2 should be in the same place as they are on the B+.