Dmitry Tyurnikov is a Russian programmer who enjoys modding games. He tends toward changing game physics using many of the mathmatics in Hyperrogue.
He has created a SPD v3.0.2 mod that uses hexagonal tiles. Although not a new concept (D&D maps used hex grids), so far as I know this is the first implimentation of hex grid physics in a PD mod.
His mod does not show up on Reddit, whose members were very anti hexagonal when proposed by others in years past.
Nor does his mod appear as a fork of SPD.
If it is on Playstore, Google's 5h!tty search engine doesn't reveal it. Although the code is posted on Github it does not appear in Micro$oft's 5h!tty search engine as a new SPD mod unless searched specifically by name. It was incidental to my researching another mod that I stumbled upon this one.
Here one can see that the DEV failed to give the mod a unique name or package name. This APK can therefor only be identified by filename or signature.
I compiled it and played just enough to get the idea and ensure the code worked. I found it was easier to click on a spot rather than move to it. If you have ever played Hyperrogue or similar hex based games, the movement is the same and just takes time to get accustomed to it. I'm not sure what can be done about the map issues to "smooth" out the edges as it were. I think the mod would have to be built from the ground up to accomplish that, or, an additional sweep would need to be done to mask it. Again, I'm not the DEV of this mod, I merely found it and thought it worth mentioning.
The DEV includes his contacts on his Git site.