If you look at their Github account, there hasn’t been a commit to their Android app in 3 years: https://github.com/kartaview/android
However, their Google Play listing shows it was last updated on February 8, 2024. https://play.google.com/store/apps/details?id=com.telenav.streetview
When Grab Holdings acquired KartaView, did they just take the open source code and start working on a proprietary copy? It’s MIT licensed which allows commercial use.
You can just take photos with any app, than upload it from a computer with the kartaview uploader, which is still foss: https://github.com/kartaview/upload-scripts
There is also the similar Panoramax/Geovisio and the full platform is foss (yet): https://gitlab.com/geovisio/web-viewer/
A public instance is hosted by osm france: https://panoramax.openstreetmap.fr No mobileapp, but you can upload on the website or with a similar cli tool: https://gitlab.com/geovisio/cli