Magi (https://sand.ai/magi) generates videos from an image.
The extension of the generated videos is possible by keeping the elements present in the initial image and adding to the first generated video in the manner of an edited movie.

Videos up to 10 seconds, reformulation of the instruction and two qualities proposed.
Sharing url and mp4 export.

500 free credits per month (10 credits per second generated in high quality and 5 in standard quality).

Edit 08/25: model now open-source https://huggingface.co/sand-ai/MAGI-1

Testing from Wikimedia image and image generated by reve.art :