I was wondering if someone with these apps has noticed what I did as described below. And if so, why is there a difference?
I just discovered that there is a difference in the HA of Polaris for my location at a given time on the iOptron app vs the Polar Scope Align Pro (PSAP) app. The difference changes with time. Sometimes is very small (1 minute or 2) to more than 20 minutes at times.
First, I have noticed that after performing a very accurate Static Polar Align (SPA) procedure (<1 degree PA error on both, az and alt) in PHD2, I was always off WRT the PSPA app by some amount. I attributed that to the polar scope reticule not being perfectly straight up and aligned with the RA axis. But I had a chance to check it and it was not that bad so I made it as correct as I could to an almost perfectly concentric rotation. Then, last night again, I was off.
I checked my location settings on the app and the iOptron Commander ASCOM driver and both match. The time is synced from the internet on both my laptop and my phone so no a chance for the difference there, The location is taken from the app and entered manually on the controller. Same values checked here too.
Then, I checked what the iOptron commander shows as Polaris position and that is where I found the difference. For the same location and time, the app gives me different HA value. For a tiebreaker, I purchased the iOptron app and it matches the commander. I guess I should have used the manufacturer app but at the time I purchase the other app I did not know it.
In any case, I like the PSAP app for the information it provides in just one app and I would like to keep/fix it if possible.