@StngBo by "constantly send data" I assume @ScruffR has anwsered your question with logging. But for your question on...
Perhaps take a look at Web Bluetooth UART Terminal In this post @RWB linked a gitlab repo with web code to do a BLE UART via web. There is even a sample webpage (Web Device CLI) up and running and you can actually use this on both ur PC and mobile to connect to a particle device via BLE if the particle is acting like a BLE UART peripheral.
Combine the web-device-cli page and https://docs.particle.io/tutorials/device-os/bluetooth-le/#uart-peripheral and you should be able to do serial connection via your phone or PC! Note on a PC you have to toggle a flag to get this to work (i.e. https://github.com/WebBluetoothCG/web-bluetooth/blob/master/implementation-status.md). Much better than an app in my opinion.
If you want to take it one step further, you can even write code to handle commands sent via serial and control your particle device via BLE. You could do something fancy like write some data to flash which upon reboot, sets the log levels that @ScruffR was mentioning.