If you tinker with electronics, then a bench power supply is one of the most useful tools you can own. It will provide nice, stable power in whatever voltage you require for a circuit, letting you power your prototypes without dealing with the hassle of batteries, voltage boosters, or a pile of different power supplies. Many also include handy features like over-current protection, which is nice for testing new unproven designs. Most bench power supplies plug into the wall, but Ember is a new battery-powered and portable bench power supply without that tether.
Most people will prefer a traditional bench power supply, but Ember is useful for people that want to tinker while traveling or that have very limited space available. Ember is small and self-contained, so it is easy to fit in a travel bag or on a small bench. It could also work well for anyone without access to stable mains power. The downside is, of course, the limited battery capacity. Ember can output power at the same time it is charging. But even so, you only get the portability benefits as long as the battery has a charge.
Ember can provide 0-15V and current from 0-1A. They aren’t huge, but those specs are enough for most embedded projects. The battery is 7Wh, which is respectable. Total working time does, of course, depend on the amount of power your project draws. The unit is just 85×75×40mm and it weighs a mere 150g. It has a USB interface that users can take advantage of to update or tweak the firmware. That same USB port allows for charging. Status and information show up on a large color LCD.
This is an open source project, so you can build your own Ember using the files provided by Blue Smoke Electronics. But if you just want an Ember without that hassle, Blue Smoke Electronics is selling prototype Ember units on Tindie for $90.