I think you're right, ping buddy needs a GPS data stream, but I was hoping that could be provided by SV as it does to FF. SV provides a higher quality GPS signal than the GPS receiver built into ipad.
I don't have Stratus, but in my readings, I noted that FF/ipad could talk to either it, or SV, but not both simultaneously. I had assumed (always a bad idea) that Stratus could Wi-Fi into the SV dongle, and thus, so could ping buddy. But I guess it can't - at least not currently.
I have an ipad Mini 4, which I bought solely for Foreflight, but I dropped it and am currently using FlyQ, which also talks to SV, the same as FF. I fly an RV-12 - big canopy, bright sunlight - for me a tablet is not the solution due to inadequate screen brightness and bad reflectivity. I've seen and flown with other RV-12 guys who have ipads bolted on in various ways and wonder what they see that I don't because their screens have major visibility problems. I can barely read my own while flying, and I have a major space problem for finding a place for it (other than my wife's lap) or juggling it while flying. One of the joys of SV is the high readability in direct sunlight (or just bright light.)
My not so secret wish is for the SV Wi-Fi dongle to accept assorted phone and tablet screen displays (as it can do with external cameras, for example), thereby allowing feeding a plethora of information to the SV screen - anything I can see on my phone or tablet. I've got the apps, I just can't see them on my portable devices.
Bob Bogash
RV-12
N737G