San Francisco-based Particle creates hardware and software to help firms like Jacuzzi and Briggs Healthcare manage their internet-of-things connected devices. The company has secured more than $75 million in funding from investors including Qualcomm, Root Ventures, and Spark Capital since its 2012 founding. Here, Particle co-founder and CEO Zach Supalla describes the one product he can't live without. --As told to Kevin J. Ryan

The reMarkable tablet is a lifesaver for people like me. I live out of my notebook and take notes constantly--it helps me remember conver­sations better and think through sticky problems. It's an e-paper tablet, so it feels basically like pen and paper, which makes the whole system more natural and flexible than some of the apps out there. Because the tablet saves everything in a digital format to the cloud, it's a great replace­ment for keeping piles of old notebooks lying around. It can even convert handwriting to typed text, and with two weeks of battery, I'm not tethered to an outlet.

For me, reMarkable is particularly powerful when combined with the bullet journal method. Bullet journaling, which has been around for a while, includes a "monthly migration"--once a month you look at your past daily logs and your future goals and make a plan for the next month. It forces you to step back periodically and ask yourself if you're doing the right things and are headed in the right direction. For me, this kind of reflection and modification is much easier when all my notes are stored and organized in a digital format.