JAS-39C 39251 belonging to the Swedish Defence Materiel Agency (FMV) Test And Evaluation Unit located in Linköping, Sweden. FMV operates around eight Gripens with one being an E version.
"The Swedish Armed Forces Materiel Administration (FMV) is a Swedish state administrative authority, which reports to the Ministry of Defense and has the task of procuring, maintaining, destroying and disposing of materiel and supplies on behalf of the Armed Forces and in this area assisting the Armed Forces in long-term material planning and supply systems." - Wikipedia
The Gripens at FMV are used for a wide range of tests, all from new weapons to refuelling and more, they are also responsible for testing newly manufactured Gripens before they get delivered to make sure that they work as they should.
You can find 39250 here: