The availability of efficient and cheap genotyping methods has facilitated genomic prediction of genotypic values of test individuals in many predominantly outcrossing crop species. The primary objective of this work was to develop a breeding prediction application that focus on prediction of F1 phenotype from crosses so that candidate parental lines that would provide promising F1 seeds could be chosen. The application was developed in the R/Shiny framework and successfully applied to a Brassica napus breeding program. From 2022, this research program has been conducting research to expand application to major horticultural crops such as peppers, tomatoes, Chinese cabbage, radishes, and cabbage. When predictive breeding was performed by generating genotype and phenotypic big data from hundreds of pure lines for each crop, the predicted superior F1 cross combination showed results consistent with those of the existing conventionally bred superior F1. The results of confirming that it is a viable platform will be presented in this Showcase.