Bug 429186

SUMMARY
I have kirigami-gallery apk downloaded from https://binary-factory.kde.org/view/Android/

I've tested it on 3 devices. The app is very laggy and slow on Samsung Galaxy J4. The scrolling experience on the "Home" page is really bad.
The same goes for all Cards* pages. The "Inline Messages" page is to much slow. This device runs heavy sites like youtube, Reddit, Instagram ..etc in firefox and Samsung internet without any issue so I'm pretty sure hardware is not to blame. 

Video:- https://player.vimeo.com/video/479808754

I've also tested it on Lenovo k8 plus which is more powerful than Samsung one but still same experience

Finally tested on Moto E7+ which newer and more powerful. Home Page and cards view scroll just fine (cause of hardware of course) but "Inline Messages" page is still slow. it is not slow as on the other two phones but it's noticeable. same as the "Home" page on Samsung and Lenovo.

The "Inline Messages" page is slowest of them all.

STEPS TO REPRODUCE
1. Install on Android
2. Scroll "Home", "Cards*" and "Inline Message" page

OBSERVED RESULT

Slow and Laggy Scrolling

EXPECTED RESULT

Smooth Scrolling

SOFTWARE/OS VERSIONS
Android 8 and 10
Qt Version: 5.15.1
Downloaded from https://binary-factory.kde.org/view/Android/job/KirigamiGallery_android/lastSuccessfulBuild/ which is build at Nov 16, 2020 4:16:00 AM

Hardware Information

(Bad Experience)
Samsung Galaxy J4 https://www.gsmarena.com/samsung_galaxy_j4-9204.php
OS Android 10 (updated)
Chipset Exynos 7570 Quad (14 nm)
CPU Quad-core 1.4 GHz Cortex-A53
GPU Mali-T720 MP2

(Bad Experience)
Lenovo k8 plus https://www.gsmarena.com/lenovo_k8_plus-8834.php
OS Android 8.0
Chipset Mediatek MT6757 Helio P25 (16 nm)
CPU Octa-core (4x2.5 GHz Cortex-A53 & 4x1.4 GHz Cortex-A53)
GPU Mali-T880MP2

(Ok Experience)
Moto E7+ https://www.gsmarena.com/motorola_moto_e7_plus-10436.php
OS Android 10
Chipset Qualcomm SM4250 Snapdragon 460 (11 nm)
CPU Octa-core (4x1.8 GHz Kryo 240 & 4x1.6 GHz Kryo 240)
GPU Adreno 610