Backpack
Software / App
A simple, no-cost alternative to a weight vest for adding resistance to walks or hikes.
Mentioned in 2 videos
Videos Mentioning Backpack

Fitness Toolkit: Protocol & Tools to Optimize Physical Health
Andrew Huberman
A simple, no-cost alternative to a weight vest for adding resistance to walks or hikes.

David Heinemeier Hansson Returns (Full Episode) | The Tim Ferriss Show (Podcast)
Tim Ferriss
A productivity and organization tool previously offered by 37signals/Basecamp, which was eventually shut down for new customers.