Don't have any Android devices, but the connectivity is bad for both my iPhone and iPad. The amp is running the latest firmware.
I guess I could open a support ticket, but I'm not sure what they can do about bluetooth working but just not very well. And even if the bluetooth connection was better, that would only address about 25% of my frustration with the Amplifi amp + app. The app really feels like software that was written to a spec but never given any real world user testing. Like cloph says above, navigation in the app itself is a total mess, and it is missing some key features. Examples:
a ) There's only half speed, no pitch change and no loop points in the music player. I'm sure that I'm not the only guitar player that uses variable speed and looping for practice. But since they aren't included I have to switch to another app to get them, but then I have to load the same song in two places to get the tone matching with the looping/speed.
b ) Storage on the amp vs storage in the cloud is a mess. There's no good way to organize My Tones or to transfer multiple presets or do a complete backup of my amp tones. If you edit a tone on your amp and go to save it, it asks if you want to save to my tones as well, and if you do it gives you multiple tones with the same name and no indication of which is the latest (unless you click through to the Details tab for each one).
c ) Editing amp tones is very slow due to sync. The amp/app don't keep track of when things changed, so each time you enter the app it has to resend the amp information which takes 10-15 seconds. A lot of the time when I'm editing tones I'm switching to a browser window to look up a player's rig to get info, and the delay each time I switch back is frustrating.
d ) No PC/Mac USB editor. I think this would help with the slow tone editing and would hopefully add a way to organize, backup, and manage presets better than the app. Plus I think a lot of us live in fear that a future iOS update will break the app and line6 will have abandoned updates. A computer based app would be much less likely to break and would give users the option to run it in a virtual machine if something did break so we could still use the amp.
In spite of all this, I've figured out workarounds to make it useable. I was thinking of returning it at one point, but overall it's still a pretty good value. I was looking into a standalone multiFX pedal with some sort of bluetooth speaker, but something like a Zoom G3 + iLoud combination would cost around $450 vs $250 for the Amplifi 75, and most of the other options wouldn't look good in a living room setting.
@cloph, maybe Lame Duck is a strong term for it, but it's really frustrating that the platform has so much potential, but Line 6 isn't giving it much attention.