First: GPS modules and phones are already installed on the Su-25 and MIG-29, but they are not for distribution as far as I understand. I saw them about a year ago.
Second, there is a very interesting modification of the Polish MIG-29, also in development.
https://www.youtube.com/watch?v=U2X4VBguA4E&ab_channel=VinntoreZ