As stated, I am out of touch with the SEEK cameras after being so disappointed with them. I had not spotted that you are STRICTLY discussing a dongle that is intended to produce >15fps. I only knew the original models that were <9fps.
Why do you not just approach SEEK and ask them why the frame rate of the Android Version is inferior to that of the iPhone version. It would cut out your guess work and the need to profile the system data processing path and budget.
I may be able to give you hint though as I already know a little about why....... when designing an application for an Apple iPhone, the developer deals with a set of known platform and interface characteristics, both in hardware and software. Developers like Apple products for this reason. Present the developers with a requirement to write an app for an Android device and see them worried. Android is, as you well know, a multi platform operating system that runs on many different hardware platforms. The differences in said hardware platforms make it very hard for the developers to optimise the app for greatest efficiency. On the iOS platform they tweak the app to provide the very best performance. On the Android platform the developers are generally very happy if the app even runs correctly on a large cross section of platforms from differing manufacturers. Android can be a total nightmare when it comes the fine tuning and squeezing maximum performance out of the app that has to drive external hardware. In many cases, the developers find platforms, in this case phones, on which they cannot achieve app stability. These go on the 'not compatible' list. It does not matter how wonderful or powerful the phone is, if the designer cannot get the app to work well on it, the phone is not a good choice.
A simple case of a fine tuned and capable dedicated app for the very well defined iOS platform Vs a generic app build designed to work 'well enough' with an acceptable range of android platforms. Fine tuning ? Dream on ! The Android App is inferior to that produced for the single platform iOS product.
Writing your own Android app is always an option, but you can discover that the SDK contains a less than ideal or sprightly driver for the camera. The reason ? It has to remain compatible with the large cross section of Android platforms on which it will run.
How do I know this to be true and 'real World' and not just some crazy theory ? Simple, I spoke at length with the people who developed the FLIR One G2 and they faced the same issues. The FLIR iOS app is more efficient than the Android app as a result. The iOS app produces a higher frame rate than the Android app even though the camera hardware is equally capable. For info, FLIR developers had to choose a single phone model for which they would try to tune the Android app so that it compared well against the iOS version when tested and reviewed. They chose the Samsung S5 mobile phone (released 2014) as the, then, equivalent to the iPhone in terms of processing power. The iPhone still achieved better frame rates though and they could not bring the Android app up to the performance of the iOS version. The FLIR One G2 Android runs at its best performance on a Samsung S5 and likely its more recent versions. SEEK may also be able to advise which phone they chose to develop the app on. Then again, they may not have bothered with fine tuning for one model and kept things generic.
So there you go, that is the answer to "why" you are seeing frame rate variances. As to how you can squeeze better performance out of your SEEK setup ? Well that is a little challenge for you to engage on, if desired. Much depends upon how helpful SEEK are with regards to release of a decent SDK
Good luck on that front !
My apologies for reducing the signal to noise ratio in this thread. I will not comment further.
Fraser