This is a super simple iphone slider rig. You can capture some really nice videos with this. I would recommend using a video stabilizer like Hyperlapse to make the video look even smoother.

https://youtu.be/3kuBrYp8WdA

Parts list:
-3d printed parts
-2 arrows
-1 smartphone tripod adapter
-1 tripod screw

Assembly instructions:
1-Cut off front of arrows(where the tip is),and cut off where the feathers start.
2-Print parts. I printed at .3 resolution, and 20% fill.
3-Hot glue the arrows to one of the bases.
4-Attach the smartphone tripod adapter to the sliding piece with the tripod screw. Slide it on to the two arrows that are glue to the base.
5-Glue on the other base.
6-Attach your phone to the smartphone holder.