The first one is a very nice white paint marker from MICADOR. It was a present and I could not find a link. But it has very nice coverage and I am always looking for a really solid black and really strong white.
The third new find is a Twist Top Squeeze Bottles (1oz) with Dispensing Caps. I filled one with the glue (that I dilute a bit) and another one with the white gouache - my fourth recent discovery: a caran d'ache white gouache eco.
Having a more liquid than usual material allows me for better coverage on large surfaces and in tight spots - which is helpful with glue. But it is an even bigger win for gouache - actually four wins:
(1) A paint that is more liquid means easier mixing.
(2) An ability to work with smaller, more precise, and sometimes more springy brushes.
(3) It gives me more control over how much paint I add.
(4) In this container, it means that the paint is not contaminated - white always stays white.