I've been looking at WizzAir's 2018 summer schedule.
They seem to have dropped Split, but are planning to operate 360 flights per week - roughly the equivalent of a 17-aircraft base - on the following routes:
Bosnia - Tuzla 2pw
Bulgaria (30) - Bourgas 3, Sofia 17, Varna 10
Czechia (10) - Brno 3, Prague 7
Georgia - Kutaisi 2
Hungary (41) - Budapest 31, Debrecen 10
Israel - Tel Aviv 4
Kosovo - Pristina 2
Latvia - Riga 14
Lithuania (25) - Kaunas 7, Palanga 4,Vilnius 14
Macedonia (7) - Ohrid 2, Skopje 5
Moldova - Chisinau 5
Poland (97) - Gdansk 19, Katowice 20, Lublin 7, Olsztyn-Mazury 3, Poznan 12, Szczecin 3, Warsaw 23, Wroclaw 10
Romania (82) - Bucharest 21, Cluj-Napoca 19, Constanta 4, Craiova 7, Iasi 7, Satu Mare 2, Sibiu 5, Suceava 5, Timisoara 7, Tirgu Mures 5
Serbia - Belgrade 3
Slovakia (6) - Kosice 3, Poprad-Tatry 3
Slovenia - Ljubljana 4
Ukraine - Kiev 4
17 countries, 41 destinations.