INSERT SCREENSLASH VIDEO + IMAGE- ICON IN THE ANDROID AND IOS APP

Hi everyone, I have 6 apps in android and 6 in ios that I made with the https://convertify.app/ service.
Of these I have the individual source codes.
To each of them I have to insert the following elements:

- App icon (which I will provide in png format)
- Screensplash intro (which I will provide in mp4 video format)
- Scrennsplash image with the insertion of forward and skip between one image and another (which I will provide in psd photoshop format)
-Inserting the onesignal app icon when the push notifications arrived that I send via onesignal (which I will provide in png format)

Can you help me with the best price and best time?
The material is all ready and I will supply it within the day

thank you very much for helping