After beta-testers' thumbs-up, NKCCluster 2.5.7 has been released to Google Play Store on 30th September 2018 and will be gradually rolled out worldwide in the coming week.
This release contains several minor bugfixes. Most notable difference in it is it now comes built for Android Oreo (8.0), but should be backwards-compatible from Android 4.1 (Jelly Bean) onwards. This latter change was stipulated in large part due to Google Play policies but it also made sense to start building NKCCluster against more stable and feature-rich platform than thus far.
This, however, means users using Android versions older than 4.1 will no loger be getting NKCCluster updates. This was a hard decision to make. Since its very first release the intention has always been to support as wide range of Android devices as possible (especially bearing in mind the radio hams' proverbial tendency to reuse old tech) but ultimately there comes a point at which there just isn't enough users to justify effort that could better be spent in delivering new functionality and better user experience on newer devices. I believe this is such point. With Android 4.1 Jelly Bean being already 6 years old and with (according to Google Play statistics) fewer than 50 users on platforms older than it, I feel I can no longer justify compromising NKCCluster performance in order to achieve maximum compatibility. If you're one of the affected users, I can only apologise to you and hope you will understand the motivation for this decision.
Please let me know if you should experience any issues with this release. Contact details are on NKCCluster's Google Play Store page.