This app was mentioned in 5 comments, with an average of 11.80 upvotes
1.) Download this Android tilt shift camera app.
2.) get Google cardboard.
Besides Snapseed, you can try out the Tilt-Shift Camera app that has gotten a lot better in last few updates.
There's some apps that will process video... for tilt shift.
https://play.google.com/store/apps/details?id=camera.tiltshift&hl=en_GB
I installed this one: https://play.google.com/store/apps/details?id=camera.tiltshift
Seems nice so far, very easy to use. The app applies the filters in real time, so the preview is a bit laggy.