The easiest way to catch the virus is on your mobile device most likely sense we bring the device home with us and continue to use it. We put out hands on it constantly even after touching doors, stair handles (at least if you touch them I rarely do unless I am feel like I am going to fall), etc.
Everything I read keeps saying that the most likely way to catch Covid-19 is through respiratory droplets yet we're constantly being told to wash our hands. Lots of research is being done into the various routes of transmission and they find that even though the virus can live for up to 3 days on some surfaces, it drops in viability not long after it no longer has a human host so it appears that touching infected surfaces isn't the most likely way people are getting sick. [WashingtonPost]
A study done on influenza and transmission on NYC subway trains done in 2011 found that only 4% of the studied cases could be traced back to transmission on the subway even though the subway train was the place that everyone feared the most. [NYTimes]
Regardless of if it's likely that you'll get sick from your phone or not, clean it regularly. It's gross. I'm a part time photographer and after I take people's official photos, they often hand me their phone and ask me to take another one for their own collection. Half the time the phones are N-A-S-T-Y!
I would also keep up the hand washing even if it's a minor way to get the virus. It could very well be that surface transmission is considered a minor route of transmission because people are getting it through direct person to person contact so regularly when we're talking a cold or the flu. In cases like the Coronavirus, it may be that because we're so much more careful with social distancing that surface transmission jumps up as a more likely route of transmission.