You can customize the look of your *Tecla App by going to the settings page by tapping the menu button (burger menu) and selecting Settings.
The available options are:
Dark theme: provide a high contrast theme (white on black) versus the standard light theme (black on white).
Font size: users can select between 3 sizes of fonts for the remote buttons, regular, large and x-large.
In settings, you can also modify your account information and link services like Amazon's Alexa and Logitech's Harmony.