How To Do Convinient Mobile App

Some interresting raw facts from article How Do Users Really Hold Mobile Devices? by Steven Hoober about using mobile devices.
Most of apps, that I am using on my Android phone does not take into account fact, that red areas exist.

How people hold and interact with mobile phones:


Two methods of holding a touchscreen phone with one hand:


The two methods of cradling a mobile phone:


Two-handed use when holding a phone vertically or horizontally:


Surely there is more interesting and useful information in the article, so I advice to read it as well, not only to look pictures.

The Pareto Principle

I can't tell that it is very useful principle, but it nice to know:
Roughly 80% of the effects come from 20% of the causes

In testing it usually means that 20% of the bugs cause 80% of the crashes. In my practice it actually works.

Good more detailed article: Understanding the Pareto Principle (The 80/20 Rule). Surely read the last paragraph "Concluding Thoughts". The important thing in this principle - it is an observation, not a law of nature.

Memory Issue On Mars

Photo by ASA/JPL-Caltech/MSSS

A computer glitch on NASA's Mars rover Curiosity has forced the robot to switch to a backup computer while engineers try to resolve the problem. In the meantime, Curiosity's science work is on hold, and the spacecraft is in a minimal-activity state known as "safe mode" while its backup computer is updated with the command codes and parameters it needs to take over the rover's full operations. "We're still early on in the process," said Richard Cook, Curiosity project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We have probably several days, maybe a week of activities to get everything back and reconfigured."

About reasons:

The computer problem is related to a glitch in flash memory on the A-side computer caused by corrupted memory files, Cook said. Scientists are still looking into the root cause the corrupted memory, but it's possible the memory files were damaged by high-energy space particles called cosmic rays, which are always a danger beyond the protective atmosphere of Earth.

The source: NASA's Mars Rover Curiosity in Safe Mode After Computer Glitch

UPD

"I don't expect there to be any long-term impact," project manager Richard Cook told Reuters. But "it's probably too early to tell." The $2.5 billion robotic geology station was in the middle of analyzing its first samples drilled out from the interior of a rock when its primary computer developed a problem on Wednesday.

Article: Computer glitch suspends NASA Mars rover operation

UPD2
Fixed:

PASADENA, Calif. - NASA's Mars rover Curiosity has transitioned from precautionary "safe mode" to active status on the path of recovery from a memory glitch last week. Resumption of full operations is anticipated by next week.

Article: Curiosity Rover's Recovery on Track