I cannot seem to boot BalenaOS on my Raspberry Pi B+. The SD card is brand new and can boot other OSes fine (Noobs, Ubuntu, Retropie etc). The Status LED flashes signifying that the Pi cannot read Kernel.img.
When adding the device on the set up page, the lowest Pi I can select is the Raspberry Pi 2, latest revision on BalenaOS and Development mode. It then creates the zip file for me. I extract the zip and can successfully burn it to the SD card. But that’s as far as I get. The pi refuses to boot.
Charles, have in mind that Raspberry Pi B+ is armv6hf, that means that if you have an application that is not compatible with armv6hf it will not work (so you are not going to see the Raspberry Pi (v1, zero, etc.) on the list.
I recommend to click the blue button Deploy with balena that you can find on the README of the repository https://github.com/balenalabs/uk-train-departure-display and then create a new application, or use an existing app with devices that are compatible with the architecture armv6hf.