Hi Camila,
We're happy to announce that this idea was implemented in the new Forum experience.
From now on, while creating a new post, the user can add the application type in the "Post context" section:

Regarding your 2nd suggestion, in the Posts list, you have now a tab with all the "unsolved" posts. The same for the tags results list:


Hope you like it!
Cheers,
Tânia