A lot of my latest work involved creating app store / portals which present available applications to (internal) customers (see example below). Usually the design is based on a dashboard with the apps as cards or tiles, similar to lotus notes or windows. When creating your own framework you can embedd the portal in your environment and business processes and e.g. reuse existing iam mechanisms or track usage.
However if you can stick with a restricted standard you can also use commercial available software – or even open source. One example is backstage (from Spotify). Main idea is to have a service or software catalog. You can customize the cards in this solution to match your desired design by adding themes when creating elements (example from the demo):
If you need a similar solution (completely programmed and flexible or based on backstage.io with customization) you can contact me.