As far as I know, if your app isn't shown in one of these drop-downs, it means that the app hasn't been properly registered in your system. You have to register your app in the system and create a
[your-app-name].desktop file (those usually reside in
A .desktop file is actually a text file, so you can open and edit it in any text editor. Among other things, a .desktop file should contain a
Categories line, which states the category of the app (one or several), which helps the system to properly categorize the app. For instance, for a music player this line usually looks like this:
If Guayadeque already has a .desktop file, please check if it contains the
On how to register apps and create .desktop files in Ubuntu you can refer to this tutorial.