I want to create a report which will contain all conversions except app installs.
How can I filter app installs?
It looks like you need to either filter by the Conversion Type Name (which would have been an App conversion related to installs/first opens) or by Conversion Category if there's a value in there that only (or mostly) applies to your app install campaigns. I could not find a Category specifically for just app installs, so either of these filters may not be 100% excluding of the app installs.
So go down the sidebar to the Filter section and depending on which field you are using, create a filter (or likely filters if using the Conversion Type Name as there's probably multiples).
Conversion category DOES NOT EQUAL Other
Conversion Type Name DOES NOT CONTAINS Install
Conversion Type Name DOES NOT EQUAL MyAppConversionName
I hope this helps. Please let us know if you have any other questions or issues.