Thank you @Vitalii_Sukhostavsky.
The Custom Apps as the name suggest are for customer-specific or account-specific use case alone. They will be visible under the specific product instance galleries and will be visible only for that account alone.
Furthermore, if the developer of the app realises that the app use case is pretty common then they can publish the same app as a marketplace app and even monetise the same. Refer to what’s new with paid apps for more details.
Once the app is published as a Marketplace app (Free/Paid) it will be listed under Freshworks Marketplace and also in the respective product galleries under the “Neo Marketplace → Marketplace Apps” section.
Regards,
Thakur