This should work fine - I don't know why the Serial Bluetooth Terminal app would disconnect. NRF Toolbox has a 'UART' button which will communicate as well.
One thing you want to watch out for is just that you need to send a newline character so your code executes.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
This should work fine - I don't know why the Serial Bluetooth Terminal app would disconnect. NRF Toolbox has a 'UART' button which will communicate as well.
One thing you want to watch out for is just that you need to send a newline character so your code executes.