Video Compressor
You have a 25 MB limit and a 40 MB video. Type the number. Get a file under it.
Every chat app, mail service and upload form has a size limit, and none of them tell you which setting gets you under it. Video Compressor works the other way round. Type the limit, pick a video, and the app finds the highest quality that fits under that number.
Everything happens on your iPhone. Nothing is uploaded, there is no account, and your original video is never changed. The compressed copy is kept in the app until you save it to Photos or share it.
If a limit is too small to reach at watchable quality, the app says so before you wait, and lets you pick a larger size or accept the quality floor. It never hands you a file that misses the number.
The first two compressions are free. After that, one purchase unlocks unlimited compressions. No subscription.