The app can be found on Google Play here.
An other later version that possibly works better can be downloaded from here, once downloaded go to "Downloads" or "Files" from where you should be able to install it.
In "Settings" > "User settings" > "Uri with authentication key for remote controller"
Click "Generate new".
Click "Copy to clipboard".
Step 2: Go back to the BLB app.
Step 3: In "Manage List" > "Add", paste the copied uri, then click save.
Step 4: Go back to the main screen and you can use the On, Off and Check buttons.