There's a ton of apps that can be added. Legion app, Market app, link skill app, forum app, chat app, there's a ton of ideas that could be added as a companion app.
At least to see what's in stock and having a less laggy search bar would be a great start. But there's a ton of companion type app that could be used for Maple.
One advice that you'll hear often is: Start by lvlupping your link skills to level 120. Evan, Mercedes, Aran, Demon Avenger, Kanna, Phantom, Beast Tamer, Xenon, Hayato, Kinesis, Cannoneer, Jett and Kaiser are few classes that you will have to level…
Terminus equips are still relevant for some classes. I believe that the terminus whip is better than fafnir but worse than arcane umbra. Plus the terminus shield is BiS for one-handed warriors.
Sadly cannoneer is one of the first link skill you want to get rid of because of his weakness. If you're not maining cannoneer, there's no point to lvlupping yours over 200 if you don't want the SSS legion block.
I would probably say that one of my earliest memory was to complete the old Maple island quests back in 2005 when you were too weak to kill orange mushrooms because you chose to become a mage
Also we could have more event shops where arcane symbols are being sold. It would be nice to have more accessible stuff that gives, for example Morass symbols so we don't have to wait 6 months to get their dailies.