for non-MGT: no and no.I'm rather confused by the licensing. Are we allowed to charge for apps? Do we need to sign some kind of licensing agreement with Marc?
For CT, MT, TNE, T4, T5, T20: you need to include the disclaimer on the splash screen or in some other easily found method. (In my interactive fiction ship walk-throughs, it's on the flyer the character starts with!)
You must note, if you open source your code, you must sanitize it - you can't include the specific traveller copyright texts. You can share your closed source code - you just cannot put it under the GPL, CC, or similar license if it includes specific elements unique to traveller.