Abstract: An Imaging Neutral Particle Analyzer (INPA) has been installed and operated at the ASDEX Upgrade (AUG) tokamak, located at the Max Planck Institute for Plasma Physics in Garching (Germany). INPA employs the operational principles of both fast-ion loss detectors (FILD) and neutral particle analyzers (NPA) to measure the fast-ion distribution in energy and radius. The FILDSIM code, which facilitates the calculation of synthetic signals for the FILD diagnostic, has undergone a major upgrade to handle the INPA diagnostic. This upgrade includes a model for simulating the scattering and energy loss of fast neutrals within the carbon foil. Additionally, it encompasses a model for estimating the scintillator yield and the capacity to conduct tomographic reconstructions. This updated code has been bench-marked against experimental data during the 2021-2022 campaign, showing an excellent agreement between simulations and measurements. Tomographic inversions also agree with neoclassical calculations during MHD quiescent phases. Fast-ion flows driven by Alfvén eigenmodes have been measured for the first time at ASDEX Upgrade. The observed flows align well with the theoretical models and with full-orbit simulations.