Many radio continuum catalogs with different sensitivity limits and spatial resolutions are published via the VizieR database. Because of the diversity of spatial resolution, the cross-identification of individual sources is complex. By assuming a power-law spectrum, the SPECFIND tool is able to handle radio surveys at different frequencies from different instruments and different resolutions. Since the former version of the SPECFIND catalog was released ten years ago, hundreds of new radio continuum catalogs have been published. We upgraded the SPECFIND tool to reach a wider frequency range, especially the lower-frequency radio regime, as well as to have better spatial sky coverage. We adapted special selection criteria to all radio tables listed in VizieR to define a final sample of new catalogs. We implemented the new catalogs into the SPECFIND tool by unifying them and then compare the results to the last version. Furthermore we present and investigate sources with spectral breaks around 1.4GHz and around 325MHz. By increasing the number of implemented SPECFIND catalogs from 115 to 204, we improve the number of resulting spectra from 107500 to 340000 and increase the number of cross-identified sources from 600000 to 1.6 million. Furthermore, we present two samples of spectral break sources. The first sample includes 3104 spectral break sources with turnover frequencies around 1.4GHz, the second sample includes 18075 spectral break sources with turnover frequencies around 325MHz. Both samples include concave sources and Gigaherz-Peaked Spectrum (GPS) or Megaherz-Peaked Spectrum (MPS) sources. The SPECFIND V3.0 catalog is a very useful resource and a powerful open access tool, reachable via VizieR. By tripling the resulting spectra and including many radio continuum surveys from the last 50 years, we provide a significantly extended catalog of cross-identified radio continuum sources. Furthermore, the SIMBAD database will be updated using the SPECFIND V3.0 catalog and will contain more radio continuum data, serving the needs of future projects.