Hi Ubaid,
I’ll be honest with you. We don’t support reverting the firmware of our devices. That’s why we don’t distribute the previous versions’ images.
The latest current firmware version, Reach Firmware 27.1, comes with new features and the latest improvements. Working with it allows you to benefit from various new features from M2M SIM card support to improved logging. Also, please note that the latest version of ReachView 3 doesn’t support Reach devices on versions lower 26 Firmware.
You can easily integrate our Reach with 3rd-party software on any firmware version. If there is a difficulty with it, please let me know and we’ll sort it out. Additionally, I’d recommend checking out our Getting Reach coordinates on Android via BT for easy steps on integration.