I do not have a smartphone with high speed video or understand any special issues using their high speed video files on Kinovea or elsewhere.
I would like to recommend that smartphones are usable directly from the smartphone or to have some idea of what is involved, such as converting to video files that are compatible with Kinovea.
Any general information or personal experiences using specific smartphones would be very informative.
Another approach would be to download all the smartphone instructions and see what they have to say. Too much...