I think some rethought needs to be put into the app. Some of my thoughts are:
1. use significantly different colors when the button for discharge or charge is on or off, maybe even an X over it when its off. Green on, red off maybe?
2. When the BT is connects to a battery the screen shows data but takes a while to update, good to have a progress bar or a busy bar while loading.
3. In the areas where is shows cell voltage, cell diffrential voltage, temperatures, battery voltage etc show allowable limits.
4. Have a place in the app with the charging profies recommended by the manufacturer.
5. if there is storage on the BMS maybe some charging/discharging curves of voltage and amps, AH consumed etc?