I know we have discussed how we all want an indicator for people wanting to raid without wasting our passes, and thought this would be an effective way to do it.
Give us a single permanent balloon in our inventory that we can add to the gym disc (like the insence slot on pokestops) to show that we are there and willing to raid.
Like HowPokemonGo on Facebook:
Would be visible from afar and could be our team colors. The balloon would be returned to your inventory when you beat the boss.
What do you think?