I'd like more text customization as well Size and a selection of fonts...when to bold...perhaps colouring options?

Both a solution and and a suggestion here: Client-side styling and scripting plugins (Stylebot, Minimalist, Stylish, etc.) allow users to develop their own text customization. RTM could easily support client-side customization by providing users with more information about the CSS selectors available within RTM and by keeping your own CSS code clean. (If the app developer is using the !important flag to solve a problem, there is some refactoring to do there.)

Just let us choose fonts, please! I prefer the font used on the RTM website on my Chromebook compared to Chrome in Windows 10. ^_^

RTM keeps changing the CSS selector used to set this font. This makes it difficult to set the font within the browser. I'm curious about the rationale for these changes.